Hello,
I recently upgraded from 4.18 to 4.26. I built the project from source on Lubuntu 18.04.5 LTS.
When I open the FPS template level I am able to click on static meshes and drag them into the world editor just fine.
Whenever I try to add static meshes to one of the levels I’ve created from scratch the editor crashes with the following error…
Assertion failed: !GIsRHIInitialized || !GRHISupportsRHIThread [File:Runtime/RHI/Public/RHIStaticStates.h] [Line: 98]
libUE4Editor-Core.so!FGenericPlatformMisc::RaiseException(unsigned int) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/Core/Private/GenericPlatform/GenericPlatformMisc.cpp:472]
libUE4Editor-Core.so!FOutputDevice::LogfImpl(char16_t const*, ...) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/Core/Private/Misc/OutputDevice.cpp:61]
libUE4Editor-Core.so!AssertFailedImplV(char const*, char const*, int, char16_t const*, __va_list_tag*) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/Core/Private/Misc/AssertionMacros.cpp:102]
libUE4Editor-Core.so!FDebug::CheckVerifyFailedImpl(char const*, char const*, int, char16_t const*, ...) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/Core/Private/Misc/AssertionMacros.cpp:455]
libUE4Editor-ChaosNiagara.so!TStaticStateRHI<TStaticSamplerState<(ESamplerFilter)1, (ESamplerAddressMode)1, (ESamplerAddressMode)1, (ESamplerAddressMode)1, 0, 1, 0u, (ESamplerCompareFunction)0>, TRefCountPtr<FRHISamplerState>, FRHISamplerState*>::FStaticStateResource::~FStaticStateResource() [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/RHI/Public/RHIStaticStates.h:98]
libc.so.6!UnknownFunction(0x43160)
libc.so.6!exit(+0x19)
libX11.so.6!_XDefaultError(+0x27)
libX11.so.6!_XError(+0x119)
libX11.so.6!UnknownFunction(0x3d7ea)
libX11.so.6!_XReply(+0x3e3)
libX11.so.6!XTranslateCoordinates(+0x8a)
libUE4Editor-ApplicationCore.so!X11_SetWindowPosition [/SDL-gui-backend/src/video/x11/SDL_x11window.c:876]
libUE4Editor-ApplicationCore.so!SDL_SetWindowPosition_REAL [/SDL-gui-backend/src/video/SDL_video.c:1962]
libUE4Editor-SlateCore.so!FDragDropOperation::OnDragged(FDragDropEvent const&) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/SlateCore/Private/Input/DragAndDrop.cpp:45]
libUE4Editor-Slate.so!FSlateUser::NotifyPointerMoveComplete(FPointerEvent const&, FWidgetPath const&) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/Slate/Private/Framework/Application/SlateUser.cpp:974]
libUE4Editor-Slate.so!FSlateApplication::RoutePointerMoveEvent(FWidgetPath const&, FPointerEvent const&, bool) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/Slate/Private/Framework/Application/SlateApplication.cpp:5200]
libUE4Editor-Slate.so!FSlateApplication::ProcessMouseMoveEvent(FPointerEvent const&, bool) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/Slate/Private/Framework/Application/SlateApplication.cpp:5594]
libUE4Editor-Slate.so!FSlateApplication::OnMouseMove() [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/Slate/Private/Framework/Application/SlateApplication.cpp:5518]
libUE4Editor-ApplicationCore.so!FLinuxApplication::ProcessDeferredMessage(SDL_Event) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/ApplicationCore/Private/Linux/LinuxApplication.cpp:336]
libUE4Editor-ApplicationCore.so!FLinuxPlatformApplicationMisc::PumpMessages(bool) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/ApplicationCore/Private/Linux/LinuxPlatformApplicationMisc.cpp:428]
UE4Editor!FEngineLoop::Tick() [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/Launch/Private/LaunchEngineLoop.cpp:4746]
UE4Editor!GuardedMain(char16_t const*) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/Launch/Private/Launch.cpp:171]
libUE4Editor-UnixCommonStartup.so!CommonUnixMain(int, char**, int (*)(char16_t const*), void (*)()) [/mnt/DATA-1/GameDev/Engines/UnrealEngine/UnrealEngine_4.26.0/UnrealEngine-release/Engine/Source/Runtime/Unix/UnixCommonStartup/Private/UnixCommonStartup.cpp:264]
libc.so.6!__libc_start_main(+0xe6)
UE4Editor!_start()