Clicking "Play" hangs entire machine in UE4Editor Linux

Hi,

I can load a fresh blank or template project (eg Third Person) in the editor and it loads fine. It renders in the viewport and I can navigate around using the mouse.

However, when I click “Play”, my machine hangs. I can’t ALT-Tab or CTRL-F1 to a terminal and I have to reboot.

I have tried running UE4Editor with the -onethread and -opengl4 flags but I get the same result. I have also tried running play in “Selected Viewport”, “New Editor Window” and “Standalone Game”. All three freeze. Standalone Game creates a new blank window with the title " 64_bit GLSL_430".

This is on Ubuntu 17.04 running kernel 4.11 and the amdgpu driver and a fresh build of UE4 4.16 preview.

There’s nothing in the output that suggests the problem (I have included the last 250 lines of the stdout + stderr).

I don’t know enough about the code base to step through it in gdb, so any suggestions would be great!

LogInit: Compiled (64-bit): May  3 2017 20:34:44
LogInit: Compiled with Clang: 3.9.1 (tags/RELEASE_391/rc2)
LogInit: Build Configuration: Development
LogInit: Branch Name: ++UE4+Release-4.16
LogInit: Command line: /home/luke/Projects/ue4test/test4_16_0/Intermediate/Shaders/tmp/00037DCF17050B04000D02FE1CFC142A/1/ 2672 1 WorkerInputOnly.in WorkerOutputOnly.out -communicatethroughfile -Multiprocess -NOPACKAGECACHE -Multiprocess
LogInit: Base directory: /home/luke/Projects/UnrealEngine/Engine/Binaries/Linux/
LogInit: Installed Engine Build: 0
[2017.05.04-01.13.36:215][  0]LogInit: Linux hardware info:
[2017.05.04-01.13.36:215][  0]LogInit:  - we are not the first instance of this executable
[2017.05.04-01.13.36:215][  0]LogInit:  - this process' id (pid) is 2739, parent process' id (ppid) is 2672
[2017.05.04-01.13.36:215][  0]LogInit:  - we are not running under debugger
[2017.05.04-01.13.36:215][  0]LogInit:  - machine network name is 'Valykrie2'
[2017.05.04-01.13.36:215][  0]LogInit:  - user name is 'luke' (luke)
[2017.05.04-01.13.36:215][  0]LogInit:  - we're logged in locally
[2017.05.04-01.13.36:215][  0]LogInit:  - we're running with rendering
[2017.05.04-01.13.36:215][  0]LogInit:  - CPU: GenuineIntel '       Intel(R) Core(TM) i5-3570K CPU @ 3.40GHz' (signature: 0x306A9)
[2017.05.04-01.13.36:215][  0]LogInit:  - Number of physical cores available for the process: 4
[2017.05.04-01.13.36:215][  0]LogInit:  - Number of logical cores available for the process: 4
[2017.05.04-01.13.36:215][  0]LogInit:  - Cache line size: 64
[2017.05.04-01.13.36:215][  0]LogInit:  - Memory allocator used: binned2
[2017.05.04-01.13.36:215][  0]LogLinux: Skipped benchmarking clocks because the engine is running in a standalone program mode - CLOCK_REALTIME will be used.
[2017.05.04-01.13.36:215][  0]LogInit: Linux-specific commandline switches:
[2017.05.04-01.13.36:215][  0]LogInit:  -nodwarf (currently OFF): suppress parsing of DWARF debug info (callstacks will be generated faster, but won't have line numbers)
[2017.05.04-01.13.36:215][  0]LogInit:  -ansimalloc - use malloc()/free() from libc (useful for tools like valgrind and electric fence)
[2017.05.04-01.13.36:215][  0]LogInit:  -jemalloc - use jemalloc for all memory allocation
[2017.05.04-01.13.36:215][  0]LogInit:  -binnedmalloc - use binned mPooling OS allocations (pool size: 1408 MB, maximum allocations: 9502).
Using binned2.
LogPlatformFile: Not using cached read wrapper
LogInit:Display: RandInit(2071142312) SRandInit(2071142312).
LogTaskGraph: Started task graph with 4 named threads and 7 total threads with 1 sets of task threads.
LogInit: Build: ++UE4+Release-4.16-CL-0
LogInit: Engine Version: 4.16.0-0+++UE4+Release-4.16
LogInit: Compatible Engine Version: 4.16.0-0+++UE4+Release-4.16
LogInit: Net CL: 0
LogDevObjectVersion: Number of dev versions registered: 16
LogDevObjectVersion:   Dev-Blueprints (B0D832E4-1F89-4F0D-ACCF-7EB736FD4AA2): 9
LogDevObjectVersion:   Dev-Build (E1C64328-A22C-4D53-A36C-8E866417BD8C): 0
LogDevObjectVersion:   Dev-Core (375EC13C-06E4-48FB-B500-84F0262A717E): 2
LogDevObjectVersion:   Dev-Editor (E4B068ED-F494-42E9-A231-DA0B2E46BB41): 17
LogDevObjectVersion:   Dev-Framework (CFFC743F-43B0-4480-9391-14DF171D2073): 23
LogDevObjectVersion:   Dev-Mobile (B02B49B5-BB20-44E9-A304-32B752E40360): 0
LogDevObjectVersion:   Dev-Networking (A4E4105C-59A1-49B5-A7C5-40C4547EDFEE): 0
LogDevObjectVersion:   Dev-Online (39C831C9-5AE6-47DC-9A44-9C173E1C8E7C): 0
LogDevObjectVersion:   Dev-Physics (78F01B33-EBEA-4F98-B9B4-84EACCB95AA2): 0
LogDevObjectVersion:   Dev-Platform (6631380F-2D4D-43E0-8009-CF276956A95A): 0
LogDevObjectVersion:   Dev-Rendering (12F88B9F-8875-4AFC-A67C-D90C383ABD29): 15
LogDevObjectVersion:   Dev-Sequencer (7B5AE74C-D270-4C10-A958-57980B212A5A): 4
LogDevObjectVersion:   Dev-VR (D7296918-1DD6-4BDD-9DE2-64A83CC13884): 0
LogDevObjectVersion:   Dev-LoadTimes (C2A15278-BFE7-4AFE-6C17-90FF531DF755): 1
LogDevObjectVersion:   Private-Geometry (6EACA3D4-40EC-4CC1-B786-8BED09428FC5): 1
LogDevObjectVersion:   Dev-AnimPhys (29E575DD-E0A3-4627-9D10-D276232CDCEA): 3
LogInit: Compiled (64-bit): May  3 2017 20:34:44
LogInit: Compiled with Clang: 3.9.1 (tags/RELEASE_391/rc2)
LogInit: Build Configuration: Development
LogInit: Branch Name: ++UE4+Release-4.16
LogInit: Command line: /home/luke/Projects/ue4test/test4_16_0/Intermediate/Shaders/tmp/00037DCF17050B04000D02FE1CFC142A/2/ 2672 2 WorkerInputOnly.in WorkerOutputOnly.out -communicatethroughfile -Multiprocess -NOPACKAGECACHE -Multiprocess
LogInit: Base directory: /home/luke/Projects/UnrealEngine/Engine/Binaries/Linux/
LogInit: Installed Engine Build: 0
[2017.05.04-01.13.36:227][  0]LogInit: Linux hardware info:
[2017.05.04-01.13.36:227][  0]LogInit:  - we are not the first instance of this executable
[2017.05.04-01.13.36:227][  0]LogInit:  - this process' id (pid) is 2740, parent process' id (ppid) is 2672
[2017.05.04-01.13.36:227][  0]LogInit:  - we are not running under debugger
[2017.05.04-01.13.36:227][  0]LogInit:  - machine network name is 'Valykrie2'
[2017.05.04-01.13.36:227][  0]LogInit:  - user name is 'luke' (luke)
[2017.05.04-01.13.36:227][  0]LogInit:  - we're logged in locally
[2017.05.04-01.13.36:227][  0]LogInit:  - we're running with rendering
[2017.05.04-01.13.36:227][  0]LogInit:  - CPU: GenuineIntel '       Intel(R) Core(TM) i5-3570K CPU @ 3.40GHz' (signature: 0x306A9)
[2017.05.04-01.13.36:227][  0]LogInit:  - Number of physical cores available for the process: 4
[2017.05.04-01.13.36:227][  0]LogInit:  - Number of logical cores available for the process: 4
[2017.05.04-01.13.36:227][  0]LogInit:  - Cache line size: 64
[2017.05.04-01.13.36:227][  0]LogInit:  - Memory allocator used: binned2
[2017.05.04-01.13.36:227][  0]LogLinux: Skipped benchmarking clocks because the engine is running in a standalone program mode - CLOCK_REALTIME will be used.
[2017.05.04-01.13.36:227][  0]LogInit: Linux-specific commandline switches:
[2017.05.04-01.13.36:227][  0]LogInit:  -nodwarf (currently OFF): suppress parsing of DWARF debug info (callstacks will be generated faster, but won't have line numbers)
[2017.05.04-01.13.36:227][  0]LogInit:  -ansimalloc - use malloc()/free() from libc (useful for tools like valgrind and electric fence)
[2017.05.04-01.13.36:227][  0]LogInit:  -jemalloc - use jemalloc for all memory allocation
[2017.05.04-01.13.36:227][  0]LogInit:  -binnedmalloc - use binned malloc  for all memory allocation
[2017.05.04-01.13.36:215][  0]LogInit:  -httpproxy=ADDRESS:PORT - redirects HTTP requests to a proxy (only supported if compiled with libcurl)
[2017.05.04-01.13.36:215][  0]LogInit:  -reuseconn - allow libcurl to reuse HTTP connections (only matters if compiled with libcurl)
[2017.05.04-01.13.36:215][  0]LogInit:  -virtmemkb=NUMBER - sets process virtual memory (address space) limit (overrides VirtualMemoryLimitInKB value from .ini)
[2017.05.04-01.13.36:215][  0]LogInit:  - Physical RAM available (not considering process quota): 32 GB (32136 MB, 32907400 KB, 33697177600 bytes)
[2017.05.04-01.13.36:215][  0]LogInit: Using OS detected language ().
[2017.05.04-01.13.36:215][  0]LogInit: Using OS detected locale ().
[2017.05.04-01.13.36:216][  0]LogTextLocalizationManager: No localization for '' exists, so 'en' will be used for the language.
[2017.05.04-01.13.36:216][  0]LogTextLocalizationManager: No localization for '' exists, so 'en' will be used for the locale.
c  for all memory allocation
[2017.05.04-01.13.36:215][  0]LogInit:  -httpproxy=ADDRESS:PORT - redirects HTTP requests to a proxy (only supported if compiled with libcurl)
[2017.05.04-01.13.36:215][  0]LogInit:  -reuseconn - allow libcurl to reuse HTTP connections (only matters if compiled with libcurl)
[2017.05.04-01.13.36:215][  0]LogInit:  -virtmemkb=NUMBER - sets process virtual memory (address space) limit (overrides VirtualMemoryLimitInKB value from .ini)
[2017.05.04-01.13.36:215][  0]LogInit:  - Physical RAM available (not considering process quota): 32 GB (32136 MB, 32907400 KB, 33697177600 bytes)
[2017.05.04-01.13.36:215][  0]LogInit: Using OS detected language ().
[2017.05.04-01.13.36:215][  0]LogInit: Using OS detected locale ().
[2017.05.04-01.13.36:215][  0]LogTextLocalizationManager: No localization for '' exists, so 'en' will be used for the language.
[2017.05.04-01.13.36:215][  0]LogTextLocalizationManager: No localization for '' exists, so 'en' will be used for the locale.
alloc  for all memory allocation
[2017.05.04-01.13.36:227][  0]LogInit:  -httpproxy=ADDRESS:PORT - redirects HTTP requests to a proxy (only supported if compiled with libcurl)
[2017.05.04-01.13.36:227][  0]LogInit:  -reuseconn - allow libcurl to reuse HTTP connections (only matters if compiled with libcurl)
[2017.05.04-01.13.36:227][  0]LogInit:  -virtmemkb=NUMBER - sets process virtual memory (address space) limit (overrides VirtualMemoryLimitInKB value from .ini)
[2017.05.04-01.13.36:227][  0]LogInit:  - Physical RAM available (not considering process quota): 32 GB (32136 MB, 32907400 KB, 33697177600 bytes)
[2017.05.04-01.13.36:227][  0]LogInit: Using OS detected language ().
[2017.05.04-01.13.36:227][  0]LogInit: Using OS detected locale ().
[2017.05.04-01.13.36:227][  0]LogTextLocalizationManager: No localization for '' exists, so 'en' will be used for the language.
[2017.05.04-01.13.36:228][  0]LogTextLocalizationManager: No localization for '' exists, so 'en' will be used for the locale.
ache/DDC.ddp not found, will not use a pak cache.
[2017.05.04-01.13.28:727][  0]LogDerivedDataCache: Unable to find inner node Pak for hierarchical cache Hierarchy.
[2017.05.04-01.13.28:727][  0]LogDerivedDataCache: FDerivedDataBackendGraph:  EnginePak pak cache file ../../../Engine/DerivedDataCache/DDC.ddp not found, will not use a pak cache.
[2017.05.04-01.13.28:727][  0]LogDerivedDataCache: Unable to find inner node EnginePak for hierarchical cache Hierarchy.
[2017.05.04-01.13.28:728][  0]LogDerivedDataCache: Using Local data cache path ../../../Engine/DerivedDataCache: Writable
[2017.05.04-01.13.28:728][  0]LogDerivedDataCache: Shared data cache path not found in *engine.ini, will not use an Shared cache.
[2017.05.04-01.13.28:728][  0]LogDerivedDataCache: Unable to find inner node Shared for hierarchical cache Hierarchy.
[2017.05.04-01.13.28:742][  0]LogSlate: Using Freetype 2.6.0
[2017.05.04-01.13.28:744][  0]LogSlate: SlateFontCache - WITH_FREETYPE: 1, WITH_HARFBUZZ: 0
[2017.05.04-01.13.28:744][  0]LogSlate: SlateFontCache - WITH_FREETYPE: 1, WITH_HARFBUZZ: 0
[2017.05.04-01.13.29:224][  0]LogLinux: Selected Device Profile: [Linux]
[2017.05.04-01.13.29:229][  0]LogContentStreaming: Texture pool size is 0.00 MB
[2017.05.04-01.13.29:438][  0]LogMeshUtilities: Using QuadricMeshReduction for automatic static mesh reduction
[2017.05.04-01.13.29:441][  0]LogMeshUtilities: No automatic skeletal mesh reduction module available
[2017.05.04-01.13.29:441][  0]LogMeshUtilities: No automatic mesh merging module available
[2017.05.04-01.13.29:441][  0]LogMeshUtilities: No distributed automatic mesh merging module available
[2017.05.04-01.13.29:704][  0]LogNetVersion: test4_16_0 , NetCL: 0, EngineNetVer: 2, GameNetVer: 0 (Checksum: 76501892)
[2017.05.04-01.13.29:943][  0]LogAssetRegistry: FAssetRegistry took 0.0113 seconds to start up
[2017.05.04-01.13.30:024][  0]LogPackageLocalizationCache: Processed 4 localized package path(s) for 2 prioritized culture(s) in 0.016277 seconds
[2017.05.04-01.13.30:029][  0]LogUObjectArray: 33921 objects as part of root set at end of initial load.
[2017.05.04-01.13.30:029][  0]LogUObjectAllocator: 7177440 out of 0 bytes used by permanent object pool.
[2017.05.04-01.13.30:029][  0]LogUObjectArray: CloseDisregardForGC: 0/0 objects in disregard for GC pool
[2017.05.04-01.13.30:127][  0]LogHAL: Linux SourceCodeAccessSettings: NullSourceCodeAccessor
[2017.05.04-01.13.33:414][  0]LogUdpMessaging: Initializing bridge on interface 0.0.0.0:0 to multicast group 230.0.0.1:6666.
[2017.05.04-01.13.33:493][  0]SourceControl: Info Source control is disabled
[2017.05.04-01.13.33:493][  0]SourceControl: Info Source control is disabled
[2017.05.04-01.13.33:502][  0]LogDesktopPlatform: DesktopPlatformLinux is not using LinuxNativeDialogs.
[2017.05.04-01.13.33:558][  0]SourceControl: Info Source control is disabled
[2017.05.04-01.13.34:111][  0]SourceControl: Info Source control is disabled
[2017.05.04-01.13.34:651][  0]LogMaterial: Uniform references updated for custom material expression Custom.
[2017.05.04-01.13.35:095][  0]LogAndroidPermission: UAndroidPermissionCallbackProxy::GetInstance
[2017.05.04-01.13.35:535][  0]LogEngine: Initializing Engine...
[2017.05.04-01.13.35:551][  0]LogMaterial: Missing cached shader map for material LevelColorationLitMaterial, compiling. Is special engine material.
[2017.05.04-01.13.36:131][  0]LogMaterial: Missing cached shader map for material LevelColorationUnlitMaterial, compiling. Is special engine material.
[2017.05.04-01.13.36:388][  0]LogMaterial: Missing cached shader map for material MAT_LevelColorationLitLightmapUV, compiling. Is special engine material.
[2017.05.04-01.13.37:111][  0]LogMaterial: Missing cached shader map for material ShadedLevelColorationLitMaterial, compiling. Is special engine material.
[2017.05.04-01.13.37:951][  0]LogMaterial: Missing cached shader map for material ShadedLevelColorationUnlitMateri, compiling. Is special engine material.
[2017.05.04-01.13.38:270][  0]LogMaterial: Missing cached shader map for material VertexColorMaterial, compiling. 
[2017.05.04-01.13.38:384][  0]LogMaterial: Missing cached shader map for material VertexColorViewMode_ColorOnly, compiling. 
[2017.05.04-01.13.38:409][  0]LogMaterial: Missing cached shader map for material VertexColorViewMode_AlphaAsColor, compiling. 
[2017.05.04-01.13.38:432][  0]LogMaterial: Missing cached shader map for material VertexColorViewMode_RedOnly, compiling. 
[2017.05.04-01.13.38:451][  0]LogMaterial: Missing cached shader map for material VertexColorViewMode_GreenOnly, compiling. 
[2017.05.04-01.13.38:478][  0]LogMaterial: Missing cached shader map for material VertexColorViewMode_BlueOnly, compiling. 
[2017.05.04-01.13.38:494][  0]LogMaterial: Missing cached shader map for material RemoveSurfaceMaterial, compiling. 
[2017.05.04-01.13.38:504][  0]LogMaterial: Missing cached shader map for material DebugMeshMaterial, compiling. 
[2017.05.04-01.13.38:539][  0]LogMaterial: Missing cached shader map for material M_InvalidLightmapSettings, compiling. 
[2017.05.04-01.13.38:590][  0]LogMaterial: Missing cached shader map for material GizmoMaterial, compiling. 
[2017.05.04-01.13.38:602][  0]LogMaterial: Missing cached shader map for material PhAT_JointLimitMaterial, compiling. 
[2017.05.04-01.13.38:619][  0]LogMaterial: Missing cached shader map for material GeomMaterial, compiling. 
[2017.05.04-01.13.38:632][  0]LogMaterial: Missing cached shader map for material EditorBrushMaterial, compiling. 
[2017.05.04-01.13.38:648][  0]LogMaterial: Missing cached shader map for material BoneWeightMaterial, compiling. 
[2017.05.04-01.13.38:758][  0]LogMaterial: Missing cached shader map for material ClothMaterial, compiling. 
[2017.05.04-01.13.38:781][  0]LogMaterial: Missing cached shader map for material PreviewShadowIndicatorMaterial, compiling. 
[2017.05.04-01.13.38:821][  0]LogStats: UGameplayTagsManager::ConstructGameplayTagTree: Construct from data asset -  0.000 s
[2017.05.04-01.13.38:821][  0]LogStats: UGameplayTagsManager::ConstructGameplayTagTree: GameplayTagTreeChangedEvent.Broadcast -  0.000 s
[2017.05.04-01.13.38:962][  0]LogAIModule: Creating AISystem for world Untitled
[2017.05.04-01.13.38:974][  0]LogALAudio: ALAudio device opened : OpenAL Soft
[2017.05.04-01.13.38:975][  0]LogALAudio: AL_VENDOR      : OpenAL Community
[2017.05.04-01.13.38:975][  0]LogALAudio: AL_RENDERER    : OpenAL Soft
[2017.05.04-01.13.38:975][  0]LogALAudio: AL_VERSION     : 1.1 ALSOFT 1.15.1
[2017.05.04-01.13.38:975][  0]LogALAudio: AL_EXTENSIONS  : AL_EXT_ALAW AL_EXT_DOUBLE AL_EXT_EXPONENT_DISTANCE AL_EXT_FLOAT32 AL_EXT_IMA4 AL_EXT_LINEAR_DISTANCE AL_EXT_MCFORMATS AL_EXT_MULAW AL_EXT_MULAW_MCFORMATS AL_EXT_OFFSET AL_EXT_source_distance_model AL_LOKI_quadriphonic AL_SOFT_buffer_samples AL_SOFT_buffer_sub_data AL_SOFTX_deferred_updates AL_SOFT_direct_channels AL_SOFT_loop_points AL_SOFT_source_latency
[2017.05.04-01.13.38:975][  0]LogInit: FAudioDevice initialized.
[2017.05.04-01.13.39:020][  0]LogDerivedDataCache: Saved boot cache 0.04s 65MB ../../../../ue4test/test4_16_0/DerivedDataCache/Boot.ddc.
[2017.05.04-01.13.39:133][  0]LogInit: Texture streaming: Enabled
[2017.05.04-01.13.39:158][  0]LogEngineSessionManager: EngineSessionManager initialized
[2017.05.04-01.13.39:639][  0]LogInit: Transaction tracking system initialized
[2017.05.04-01.13.39:971][  0]BlueprintLog: New page: Editor Load
[2017.05.04-01.13.41:025][  0]LocalizationService: Info Localization service is disabled
[2017.05.04-01.13.41:317][  0]LogTcpMessaging: Initializing TcpMessaging bridge
[2017.05.04-01.13.41:688][  0]LogConsoleResponse:Display: 
[2017.05.04-01.13.41:707][  0]LogMaterial: Missing cached shader map for material Cross_Mat, compiling. 
[2017.05.04-01.13.41:750][  0]LogMaterial: Missing cached shader map for material PhAT_BoneSelectedMaterial, compiling. 
[2017.05.04-01.13.41:787][  0]LogMaterial: Missing cached shader map for material PhAT_ElemSelectedMaterial, compiling. 
[2017.05.04-01.13.41:816][  0]LogMaterial: Missing cached shader map for material PhAT_NoCollisionMaterial, compiling. 
[2017.05.04-01.13.41:849][  0]LogMaterial: Missing cached shader map for material PhAT_UnselectedMaterial, compiling. 
[2017.05.04-01.13.41:878][  0]LogMaterial: Missing cached shader map for material Tick_Mat, compiling. 
[2017.05.04-01.13.41:903][  0]LogMaterial: Missing cached shader map for material WidgetGridVertexColorMaterial_Ma, compiling. 
[2017.05.04-01.13.41:920][  0]LogMaterial: Missing cached shader map for material WidgetMaterial, compiling. 
[2017.05.04-01.13.41:934][  0]LogMaterial: Missing cached shader map for material WidgetMaterial_Current, compiling. 
[2017.05.04-01.13.41:949][  0]LogMaterial: Missing cached shader map for material WidgetMaterial_X, compiling. 
[2017.05.04-01.13.41:964][  0]LogMaterial: Missing cached shader map for material WidgetMaterial_Y, compiling. 
[2017.05.04-01.13.41:978][  0]LogMaterial: Missing cached shader map for material WidgetMaterial_Z, compiling. 
[2017.05.04-01.13.41:993][  0]LogMaterial: Missing cached shader map for material WidgetVertexColorMaterial, compiling. 
[2017.05.04-01.13.42:044][  0]LogMaterial: Missing cached shader map for material LevelGridMaterial, compiling. 
[2017.05.04-01.13.42:081][  0]LogMaterial: Missing cached shader map for material BlinkingCaret, compiling. 
[2017.05.04-01.13.42:108][  0]LogMaterial: Missing cached shader map for material M_StreamingPause, compiling. 
[2017.05.04-01.13.42:138][  0]LogFileCache: Scanning file cache for directory '/home/luke/Projects/ue4test/test4_16_0/Content/' took 0.00s
[2017.05.04-01.13.42:138][  0]LogCook:Display: Max memory allowance for cook 16384mb min free memory 0mb
[2017.05.04-01.13.42:139][  0]LogCook:Display: Mobile HDR setting 1
[2017.05.04-01.13.43:088][  0]SourceControl: Info Source control is disabled
[2017.05.04-01.13.43:088][  0]Cmd: MAP LOAD FILE="../../../../ue4test/test4_16_0/Content/ThirdPersonBP/Maps/ThirdPersonExampleMap.umap" TEMPLATE=0 SHOWPROGRESS=1 FEATURELEVEL=3
[2017.05.04-01.13.43:089][  0]LightingResults: New page: Lighting Build
[2017.05.04-01.13.43:128][  0]MapCheck: New page: Map Check
[2017.05.04-01.13.43:128][  0]LightingResults: New page: Lighting Build
[2017.05.04-01.13.43:679][  0]LogMaterial: Missing cached shader map for material M_Sky_Panning_Clouds2, compiling. 
[2017.05.04-01.13.43:916][  0]LogMaterial: Missing cached shader map for material M_UE4Man_Body, compiling. 
[2017.05.04-01.13.44:036][  0]LogMaterial: Missing cached shader map for material M_UE4Man_Body, compiling. 
[2017.05.04-01.13.44:294][  0]LogMaterial: Missing cached shader map for material CubeMaterial, compiling. 
[2017.05.04-01.13.44:326][  0]LogMaterial: Missing cached shader map for material RampMaterial, compiling. 
[2017.05.04-01.13.44:357][  0]LogAIModule: Creating AISystem for world ThirdPersonExampleMap
[2017.05.04-01.13.44:372][  0]LogEditorServer: Finished looking for orphan Actors (0.000 secs)
[2017.05.04-01.13.44:400][  0]Cmd: MAP CHECKDEP NOCLEARLOG
[2017.05.04-01.13.44:425][  0]MapCheck: Info Map check complete: 0 Error(s), 0 Warning(s), took 24.552ms to complete.
[2017.05.04-01.13.44:425][  0]LogFileHelpers: Loading map 'ThirdPersonExampleMap' took 1.336
[2017.05.04-01.13.44:768][  0]LogCollectionManager: Loaded 0 collections in 0.001386 seconds
[2017.05.04-01.13.44:793][  0]LogFileCache: Scanning file cache for directory '/home/luke/Projects/ue4test/test4_16_0/Saved/Collections/' took 0.00s
[2017.05.04-01.13.44:793][  0]LogFileCache: Scanning file cache for directory '/home/luke/Projects/ue4test/test4_16_0/Content/Developers/luke/Collections/' took 0.00s
[2017.05.04-01.13.44:793][  0]LogFileCache: Scanning file cache for directory '/home/luke/Projects/ue4test/test4_16_0/Content/Collections/' took 0.00s
[2017.05.04-01.13.44:793][  0]LogContentBrowser: Native class hierarchy populated in 0.0165 seconds. Added 2313 classes and 464 folders.
[2017.05.04-01.13.44:798][  0]LogCollectionManager: Rebuilt the GUID cache for 0 collections in 0.000001 seconds
[2017.05.04-01.13.44:914][  0]LogContentBrowser: Native class hierarchy updated for 'WidgetCarousel' in 0.0096 seconds. Added 0 classes and 0 folders.
[2017.05.04-01.13.45:006][  0]LogContentBrowser: Native class hierarchy updated for 'AddContentDialog' in 0.0006 seconds. Added 0 classes and 0 folders.
[2017.05.04-01.13.45:094][  0]LogContentBrowser: Native class hierarchy updated for 'SceneOutliner' in 0.0012 seconds. Added 1 classes and 2 folders.
[2017.05.04-01.13.45:224][  0]LogCrashTracker: Crashtracker disabled due to settings.
e[33m[2017.05.04-01.13.45:235][  0]LogUObjectGlobals:Warning: Failed to find object 'Class None.'
e[0m[2017.05.04-01.13.45:289][  0]LogContentBrowser: Native class hierarchy updated for 'HierarchicalLODOutliner' in 0.0011 seconds. Added 1 classes and 2 folders.
[2017.05.04-01.13.45:289][  0]LogLoad: (Engine Initialization) Total time: 24.58 seconds
[2017.05.04-01.13.45:289][  0]LogLoad: (Engine Initialization) Total Blueprint compile time: 0.21 seconds
[2017.05.04-01.13.45:290][  0]LogExternalProfiler: No external profilers were discovered.  External profiling features will not be available.
[2017.05.04-01.13.45:637][  0]LogSlate: Took 0.000105 seconds to synchronously load lazily loaded font '../../../Engine/Content/Slate/Fonts/Roboto-Regular.ttf' (155K)
[2017.05.04-01.13.45:641][  0]LogSlate: Took 0.000078 seconds to synchronously load lazily loaded font '../../../Engine/Content/Slate/Fonts/Roboto-Bold.ttf' (160K)
[2017.05.04-01.13.45:657][  0]LogSlate: Took 0.000562 seconds to synchronously load lazily loaded font '../../../Engine/Content/Editor/Slate/Fonts/FontAwesome.ttf' (139K)
[2017.05.04-01.13.45:735][  0]LogMaterial: Missing cached shader map for material LevelGridMaterial2, compiling. 
[2017.05.04-01.13.45:831][  0]LogRenderer: Reallocating scene render targets to support 1056x532 NumSamples 1 (Frame:1).
[2017.05.04-01.13.46:092][  0]LogLinux: Setting swap interval to 'Immediate'
[2017.05.04-01.13.46:092][  0]LogInit: Adding external input plugin.
[2017.05.04-01.13.46:158][  0]LogContentBrowser: Native class hierarchy updated for 'SteamVR' in 0.0011 seconds. Added 2 classes and 0 folders.
[2017.05.04-01.13.46:185][  0]LogContentStreaming: Texture pool size now 1000 MB
[2017.05.04-01.13.46:251][  0]LogSlate: Took 0.000412 seconds to synchronously load lazily loaded font '../../../Engine/Content/Slate/Fonts/Roboto-Light.ttf' (159K)
[2017.05.04-01.13.46:318][  2]LogAssetRegistry: Asset discovery search completed in 16.3810 seconds
[2017.05.04-01.13.46:320][  2]LogCollectionManager: Rebuilt the object cache for 0 collections in 0.000000 seconds (found 0 objects)
[2017.05.04-01.13.46:320][  2]LogCollectionManager: Fixed up redirectors for 0 collections in 0.000081 seconds (updated 0 objects)
[2017.05.04-01.13.47:385][ 78]LogLinux: Setting swap interval to 'Immediate'
[2017.05.04-01.14.11:799][873]LogLinux: Setting swap interval to 'Immediate'
[2017.05.04-01.14.12:105][896]LogTemp: Repeting last play command: Selected Viewport
[2017.05.04-01.14.12:154][896]LogBlueprintUserMessages: Early PlayInEditor Detection: Level '/Game/ThirdPersonBP/Maps/ThirdPersonExampleMap.ThirdPersonExampleMap:PersistentLevel' has LevelScriptBlueprint '/Game/ThirdPersonBP/Maps/ThirdPersonExampleMap.ThirdPersonExampleMap:PersistentLevel.ThirdPersonExampleMap' with GeneratedClass '/Game/ThirdPersonBP/Maps/ThirdPersonExampleMap.ThirdPersonExampleMap_C' with ClassGeneratedBy '/Game/ThirdPersonBP/Maps/ThirdPersonExampleMap.ThirdPersonExampleMap:PersistentLevel.ThirdPersonExampleMap'
[2017.05.04-01.14.12:154][896]LogPlayLevel: PlayLevel: No blueprints needed recompiling
[2017.05.04-01.14.12:155][896]PIE: New page: PIE session: ThirdPersonExampleMap (4 May 2017 9:14:12 pm)
[2017.05.04-01.14.12:155][896]LogPlayLevel: Creating play world package: /Game/ThirdPersonBP/Maps/UEDPIE_0_ThirdPersonExampleMap
[2017.05.04-01.14.12:167][896]LogPlayLevel: PIE: StaticDuplicateObject took: (0.011219s)
[2017.05.04-01.14.12:167][896]LogAIModule: Creating AISystem for world ThirdPersonExampleMap
[2017.05.04-01.14.12:167][896]LogPlayLevel: PIE: World Init took: (0.000698s)
[2017.05.04-01.14.12:167][896]LogPlayLevel: PIE: Created PIE world by copying editor world from /Game/ThirdPersonBP/Maps/ThirdPersonExampleMap.ThirdPersonExample

It also crashes with the “radeon” driver but gives a message:

kernel: [ 202.157121] Fixing recursive fault but reboot is needed!

Well, both the behavior and the kernel message suggests that the root of the issue is the driver. While it is very often that driver bugs are triggered by uncommon or incorrect client code (in this case, UE4 code), the same problem does not happen with other drivers, so I would not assume UE4’s bug from the get-go. You’d need to debug amdgpu first to figure out where the problem lies.

Both the amdgpu and radeon drivers hang. radeon at least says “kernel: [ 202.157121] Fixing recursive fault but reboot is needed!”

I’m thinking this might be an underlying mesa issue.

What’s perplexing is that the editor viewport renders everything perfectly, it’s just pressing play hangs the machine.

So after more investigation, the problem is possibly that GL_EXT_gpu_shader4 is being reported by the linux mesa drivers as supported but it is not fully supported. I have opened a ticket with the mesa/amdgpu folk but it may take a while.

Is it possible to force u4editor “play” to not use this extension?