Mac xbuild Compiler crashed with code: 255

…/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.CSharp.targets: error : Compiler crashed with code: 255.

When trying to execute GenerateProjectFiles.command on my mac it throws above error. It occurs in
…/Engine/Build/BatchFiles/Mac/GenerateProjectFiles.sh
with command
xbuild …/…/…/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj /property:Configuration=“Development” /verbosity:quiet /nologo |grep -i

I have no idea how to solve this :s.

Edit:
Giving some more detail : )
Log:

:UnrealEngine  $ ./GenerateProjectFiles.command 

Setting up Unreal Engine 4 project files...

Setting up Mono
XBuild Engine Version 3.2.6.0
Mono, Version 3.2.6.0
Copyright (C) Marek Sieradzki 2005-2008, Novell 2008-2011.
:  warning : Default tasks file /Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/2.0/Microsoft.Common.tasks not found, ignoring.

Build started 06/12/2014 14:20:19.
__________________________________________________
Project "/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj" (default target(s)):
	Target PrepareForBuild:
		Configuration: Development Platform: AnyCPU
	Target GetReferenceAssemblyPaths:
/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.Common.targets:  warning : Unable to find framework corresponding to target framework moniker '.NETFramework,Version=v4.5'. Framework assembly references will be resolved from GAC, which might not be intended behavior.
	Target ResolveAssemblyReferences:
/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.Common.targets:  warning : Reference 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' not resolved
		For searchpath /Users/ /programs/UnrealEngine/Engine/Binaries/DotNET
		Considered '/Users/ /programs/UnrealEngine/Engine/Binaries/DotNET/mscorlib' as a file, but file does not exist
		Considered '/Users/ /programs/UnrealEngine/Engine/Binaries/DotNET/mscorlib.exe' as a file, but file does not exist
		Considered '/Users/ /programs/UnrealEngine/Engine/Binaries/DotNET/mscorlib.dll' as a file, but file does not exist
		For searchpath {CandidateAssemblyFiles}
		Warning: {CandidateAssemblyFiles} not supported currently
		For searchpath {HintPathFromItem}
		HintPath attribute not found
		For searchpath {TargetFrameworkDirectory}
		For searchpath {PkgConfig}
		Considered mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, but could not find in any pkg-config files.
		For searchpath {GAC}
		Considered mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, but could not find in GAC.
		For searchpath {RawFileName}
		Considered '/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' as a file, but file does not exist
		For searchpath ../../../Binaries/DotNET/
/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.Common.targets:  warning : Reference 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' not resolved
		For searchpath /Users/ /programs/UnrealEngine/Engine/Binaries/DotNET
		For searchpath {CandidateAssemblyFiles}
		Warning: {CandidateAssemblyFiles} not supported currently
		For searchpath {HintPathFromItem}
		HintPath attribute not found
		For searchpath {TargetFrameworkDirectory}
		For searchpath {PkgConfig}
		Considered mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, but could not find in any pkg-config files.
		For searchpath {GAC}
		Considered mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, but could not find in GAC.
		For searchpath {RawFileName}
		For searchpath ../../../Binaries/DotNET/ 
	Target GenerateSatelliteAssemblies:
	No input files were specified for target GenerateSatelliteAssemblies, skipping.
	Target GenerateTargetFrameworkMonikerAttribute:
	Skipping target "GenerateTargetFrameworkMonikerAttribute" because its outputs are up-to-date.
	Target CoreCompile:
		Tool /Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/bin/mcs execution started with arguments: /noconfig /debug:pdbonly /optimize+ /out:obj/Development/UnrealBuildTool.exe ../DotNETCommon/MetaData.cs Configuration/UEBuildClient.cs Configuration/UEBuildDeploy.cs Configuration/UEBuildBinary.cs Configuration/UEBuildEditor.cs Configuration/UEBuildGame.cs Configuration/UEBuildModule.cs Configuration/UEBuildPlatform.cs Configuration/UEBuildServer.cs fastJSON/Formatter.cs fastJSON/Getters.cs fastJSON/JSON.cs fastJSON/JsonParser.cs fastJSON/JsonSerializer.cs fastJSON/Reflection.cs fastJSON/SafeDictionary.cs HTML5/HTML5ProjectGenerator.cs HTML5/HTML5ToolChain.cs HTML5/UEBuildHTML5.cs IOS/IOSProjectGenerator.cs IOS/IOSToolChain.cs IOS/UEBuildIOS.cs Linux/LinuxProjectGenerator.cs Linux/LinuxToolChain.cs Linux/UEBuildLinux.cs Properties/AssemblyInfo.cs Configuration/UEBuildConfiguration.cs Configuration/UEBuildTarget.cs System/ActionGraph.cs System/ActionHistory.cs System/BuildException.cs Configuration/BuildConfiguration.cs System/DirectoryLookupCache.cs System/CPPEnvironment.cs System/CPPHeaders.cs System/DependencyCache.cs System/DynamicCompilation.cs System/ExternalExecution.cs System/FileItem.cs System/JunkDeleter.cs System/LinkEnvironment.cs System/LocalExecutor.cs System/MakefileGenerator.cs System/Plugins.cs System/Project.cs System/ProjectFileGenerator.cs System/ResponseFile.cs System/RPCUtilHelper.cs System/RulesCompiler.cs System/SourceFileSearch.cs System/Telemetry.cs System/ThirdPartyHeaderFinder.cs System/UEPlatformProjectGenerator.cs System/Unity.cs System/UnrealBuildTool.cs System/UProjectInfo.cs System/Utils.cs System/VCProject.cs System/VCProjectFileGenerator.cs System/XcodeProject.cs System/XcodeProjectFileGenerator.cs ToolChain/RemoteToolChain.cs ToolChain/UEToolChain.cs System/XGE.cs Utilities/CopyrightVerify.cs Utilities/DictionaryExtensions.cs Utilities/XmlConfigLoader.cs Utilities/GraphVisualization.cs Windows/UEBuildWindows.cs Windows/VCToolChain.cs Windows/WindowsProjectGenerator.cs Mac/MacToolChain.cs Mac/UEBuildMac.cs Mac/MacProjectGenerator.cs Configuration/EngineConfiguration.cs IOS/UEDeployIOS.cs System/ModuleProcessingException.cs System/VCSolutionOptions.cs /target:exe /define:TRACE /platform:AnyCPU /reference:../../../Binaries/DotNET/Ionic..Reduced.dll /reference:../../../Binaries/DotNET/RPCUtility.exe /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System/4.0.0.0__b77a5c561934e089/System.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Data/4.0.0.0__b77a5c561934e089/System.Data.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Management/4.0.0.0__b03f5f7f11d50a3a/System.Management.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Web.Extensions/4.0.0.0__31bf3856ad364e35/System.Web.Extensions.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Xml/4.0.0.0__b77a5c561934e089/System.Xml.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Xml.Linq/4.0.0.0__b77a5c561934e089/System.Xml.Linq.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Core/4.0.0.0__b77a5c561934e089/System.Core.dll /warn:4
/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.CSharp.targets: error : Compiler crashed with code: 255.
	Task "Csc" execution -- FAILED
	Done building target "CoreCompile" in project "/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj".-- FAILED
Done building project "/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj".-- FAILED

Build FAILED.

Warnings:

:  warning : Default tasks file /Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/2.0/Microsoft.Common.tasks not found, ignoring.

/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj (default targets) ->
/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.Common.targets (GetReferenceAssemblyPaths target) ->

	/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.Common.targets:  warning : Unable to find framework corresponding to target framework moniker '.NETFramework,Version=v4.5'. Framework assembly references will be resolved from GAC, which might not be intended behavior.

/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj (default targets) ->
/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.Common.targets (ResolveAssemblyReferences target) ->

	/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.Common.targets:  warning : Reference 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' not resolved
	/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.Common.targets:  warning : Reference 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' not resolved

Errors:

/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj (default targets) ->
/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.CSharp.targets (CoreCompile target) ->

	/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.CSharp.targets: error : Compiler crashed with code: 255.

	 4 Warning(s)
	 1 Error(s)

Time Elapsed 00:00:00.3320820
assembly mscorlib.dll was not found or could not be loaded.
It should have been installed in the `/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/2.0/mscorlib.dll' directory.

I could solve mscorlib problem by copying

/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/mscorlib.dll 

to

/Users//programs/UnrealEngine/Engine/Binaries/DotNET/mscorlib.dll .

Which now leaves me with:

:UnrealEngine  $ ./GenerateProjectFiles.command 

Setting up Unreal Engine 4 project files...

Setting up Mono
XBuild Engine Version 3.2.6.0
Mono, Version 3.2.6.0
Copyright (C) Marek Sieradzki 2005-2008, Novell 2008-2011.
:  warning : Default tasks file /Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/2.0/Microsoft.Common.tasks not found, ignoring.

Build started 06/12/2014 15:00:44.
__________________________________________________
Project "/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj" (default target(s)):
	Target PrepareForBuild:
		Configuration: Development Platform: AnyCPU
	Target GetReferenceAssemblyPaths:
/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.Common.targets:  warning : Unable to find framework corresponding to target framework moniker '.NETFramework,Version=v4.5'. Framework assembly references will be resolved from GAC, which might not be intended behavior.
	Target GenerateSatelliteAssemblies:
	No input files were specified for target GenerateSatelliteAssemblies, skipping.
	Target GenerateTargetFrameworkMonikerAttribute:
	Skipping target "GenerateTargetFrameworkMonikerAttribute" because its outputs are up-to-date.
	Target CoreCompile:
		Tool /Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/bin/mcs execution started with arguments: /noconfig /debug:pdbonly /optimize+ /out:obj/Development/UnrealBuildTool.exe ../DotNETCommon/MetaData.cs Configuration/UEBuildClient.cs Configuration/UEBuildDeploy.cs Configuration/UEBuildBinary.cs Configuration/UEBuildEditor.cs Configuration/UEBuildGame.cs Configuration/UEBuildModule.cs Configuration/UEBuildPlatform.cs Configuration/UEBuildServer.cs fastJSON/Formatter.cs fastJSON/Getters.cs fastJSON/JSON.cs fastJSON/JsonParser.cs fastJSON/JsonSerializer.cs fastJSON/Reflection.cs fastJSON/SafeDictionary.cs HTML5/HTML5ProjectGenerator.cs HTML5/HTML5ToolChain.cs HTML5/UEBuildHTML5.cs IOS/IOSProjectGenerator.cs IOS/IOSToolChain.cs IOS/UEBuildIOS.cs Linux/LinuxProjectGenerator.cs Linux/LinuxToolChain.cs Linux/UEBuildLinux.cs Properties/AssemblyInfo.cs Configuration/UEBuildConfiguration.cs Configuration/UEBuildTarget.cs System/ActionGraph.cs System/ActionHistory.cs System/BuildException.cs Configuration/BuildConfiguration.cs System/DirectoryLookupCache.cs System/CPPEnvironment.cs System/CPPHeaders.cs System/DependencyCache.cs System/DynamicCompilation.cs System/ExternalExecution.cs System/FileItem.cs System/JunkDeleter.cs System/LinkEnvironment.cs System/LocalExecutor.cs System/MakefileGenerator.cs System/Plugins.cs System/Project.cs System/ProjectFileGenerator.cs System/ResponseFile.cs System/RPCUtilHelper.cs System/RulesCompiler.cs System/SourceFileSearch.cs System/Telemetry.cs System/ThirdPartyHeaderFinder.cs System/UEPlatformProjectGenerator.cs System/Unity.cs System/UnrealBuildTool.cs System/UProjectInfo.cs System/Utils.cs System/VCProject.cs System/VCProjectFileGenerator.cs System/XcodeProject.cs System/XcodeProjectFileGenerator.cs ToolChain/RemoteToolChain.cs ToolChain/UEToolChain.cs System/XGE.cs Utilities/CopyrightVerify.cs Utilities/DictionaryExtensions.cs Utilities/XmlConfigLoader.cs Utilities/GraphVisualization.cs Windows/UEBuildWindows.cs Windows/VCToolChain.cs Windows/WindowsProjectGenerator.cs Mac/MacToolChain.cs Mac/UEBuildMac.cs Mac/MacProjectGenerator.cs Configuration/EngineConfiguration.cs IOS/UEDeployIOS.cs System/ModuleProcessingException.cs System/VCSolutionOptions.cs /target:exe /define:TRACE /platform:AnyCPU /reference:../../../Binaries/DotNET/Ionic..Reduced.dll /reference:../../../Binaries/DotNET/RPCUtility.exe /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System/4.0.0.0__b77a5c561934e089/System.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Data/4.0.0.0__b77a5c561934e089/System.Data.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Management/4.0.0.0__b03f5f7f11d50a3a/System.Management.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Web.Extensions/4.0.0.0__31bf3856ad364e35/System.Web.Extensions.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Xml/4.0.0.0__b77a5c561934e089/System.Xml.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Xml.Linq/4.0.0.0__b77a5c561934e089/System.Xml.Linq.dll /reference:/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/gac/System.Core/4.0.0.0__b77a5c561934e089/System.Core.dll /warn:4
/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.CSharp.targets: error : Compiler crashed with code: 255.
	Task "Csc" execution -- FAILED
	Done building target "CoreCompile" in project "/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj".-- FAILED
Done building project "/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj".-- FAILED

Build FAILED.

Warnings:

:  warning : Default tasks file /Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/2.0/Microsoft.Common.tasks not found, ignoring.

/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj (default targets) ->
/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.Common.targets (GetReferenceAssemblyPaths target) ->

	/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.Common.targets:  warning : Unable to find framework corresponding to target framework moniker '.NETFramework,Version=v4.5'. Framework assembly references will be resolved from GAC, which might not be intended behavior.

Errors:

/Users/ /programs/UnrealEngine/Engine/Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj (default targets) ->
/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.CSharp.targets (CoreCompile target) ->

	/Users/ /programs/UnrealEngine/Engine/Binaries/ThirdParty/Mono/Mac/lib/mono/4.0/Microsoft.CSharp.targets: error : Compiler crashed with code: 255.

	 2 Warning(s)
	 1 Error(s)

Time Elapsed 00:00:00.2629040
assembly mscorlib.dll was not found or could not be loaded.

Hey ,

Can you check and see if you have latest dependencies? You can find latest for 4.2 here:

https://github.com/EpicGames/UnrealEngine/releases/tag/4.2.0-release

Download and install Required_1of2 and 2of2 again, just in case something got corrupted. If you still run into this issue, let us know!

Ok, that helped : ). Got engine built as
“UE4Editor - Mac” for “My Mac 64-bit”.

Now I have a .uproject file. Right-Click → Generate Xcode Project does nothing.
Using

UnrealEngine/Engine/Build/BatchFiles/Mac/GenerateProjectFiles.sh -project="../../../../../ProjectName/ProjectName.uproject" -game

generates error
Setting up Unreal Engine 4 project files…

Setting up Mono
Discovering modules, targets and source code for game...
UnrealBuildTool Exception: ERROR: Failed to launch compiler to compile assembly from source files 'System.Collections.Generic.List`1[System.String]' (Exception: Compiler failed to produce assembly. Output: '')

I had same error when trying to compile engine with target “BlankProgram - Mac”.

I edited line in GenerateProjectFiles.sh from

mono ../../../Binaries/DotNET/UnrealBuildTool.exe -XcodeProjectFile "$@"

to

mono ../../../Binaries/DotNET/UnrealBuildTool.exe UE4Editor -XcodeProjectFile "$@"

That still throws same error though.
Before it wanted to access a folder in /User/“ProjectName”, which I had to create and grant chmod access. Copying my project into that folder still throws same error.

I have no idea where to look further from now on.
Any ideas appreciated : )!!

Best regards!

Hey ,

Sorry for delay in response. Are you following instructions listed on GitHub site for Mac?

  1. Be sure to have Xcode 5.1 installed.

  2. You’ll need project files in order to compile. In UnrealEngine folder, double-click on GenerateProjectFiles.command. It should take less than a minute to complete. You can close Terminal window afterwards. If you downloaded source in . format, you may see a warning about an unidentified developer. This is because because the . files on GitHub are not digitally signed. To work around this, right-click on GenerateProjectFiles.command, select Open, then click Open button if you are sure you want to open it.

  3. Load project into Xcode by double-clicking on UE4.xcodeproj file.

  4. It’s time to compile editor! In Xcode, build UE4Editor - Mac target for My Mac by selecting it in target drop down in top left, then using Product → Build For → Running. It will take between 15 and 40 minutes, depending on your system specs.

  5. After compiling finishes, you can load editor from Xcode using Product → Run menu command!

Well, all that works.

problem now is, that I have a .uproject file which I want to generate. I pretty much described what happens in prior post. Right-clicking the .uproject file and clicking “Generate Xcode Project” does nothing.

I got a little further with command
UnrealEngine/Engine/Build/BatchFiles/Mac/GenerateProjectFiles.sh -project=“…/…/…/…/…/ProjectName/ProjectName.uproject” -game

See prior post for errors I get when executing that command. (Is command correct for generating project files? I found it on internet).

You shouldn’t have to Generate Xcode Project to access your project. What type of project have you created? Is it a Blueprint or C++ project? Is there any reason you’re trying to generate an xcode project?

Hm, well I wouldn’t know how to get my Xcode project files then. It’s described way (Managing Game Code in Unreal Engine | Unreal Engine 5.1 Documentation).

command “GenerateProjectFiles.sh …” I got from Why can't I generate XCode files? - Platform & Builds - Epic Developer Community Forums .

Ah, I see, I misunderstood. You should be able to create your [ProjectName].xcodeproj by right-clicking and selecting Generate Xcode Project, as you described. This works fine on my machine, so I’ll try to get a developer to look into issue for you. In meantime, creating a C++ project will auto-generate the .xcodeproject file for you if you just want to get started.

Do you have Mono installed on your Mac? If you do, let me know what version (open Terminal app and type mono --version). It’s likely that our build system tries to use version you have installed instead of one bundled with engine and you have a version that’s somehow incompatible.

If that’s case, try editing Engine/Build/BatchFiles/Mac/SetupMono.sh script and comment out lines 24 and 30 with #:

24: #if [ $IS_MONO_INSTALLED -eq 0 ]; then

30: #fi

Hey ,

We haven’t heard back from you in a while, so I am marking this post as resolved for tracking purposes. Please feel free to reopen if you are still experiencing issue. Thanks!

mono --version

gives me:

-bash: mono: command not found

I guess mono is not installed on my machine then?

Also, uncommenting lines
24: #if [ $IS_MONO_INSTALLED -eq 0 ]; then

30: #fi

in Engine/Build/BatchFiles/Mac/SetupMono.sh does not help.

current error I get is

 ./GenerateProjectFiles.sh -project=../../../../../../../../Users/Supraball/Supraball.uproject -game

Setting up Unreal Engine 4 project files...

Setting up Mono
Discovering modules, targets and source code for game...
UnrealBuildTool Exception: System.UriFormatException: Invalid URI: format of URI could not be determined: Users/Supraball/
  at System.Uri..ctor (System.String uriString, Boolean dontEscape) [0x00000] in <filename unknown>:0 
  at System.Uri..ctor (System.String uriString) [0x00000] in <filename unknown>:0 
  at UnrealBuildTool.Utils.MakePathRelativeTo (System.String SourcePath, System.String RelativeToDirectory, Boolean AlwaysTreatSourceAsDirectory) [0x00000] in <filename unknown>:0 
  at UnrealBuildTool.ProjectFileGenerator.AddUnrealBuildToolProject (UnrealBuildTool.MasterProjectFolder ProgramsFolder) [0x00000] in <filename unknown>:0 
  at UnrealBuildTool.ProjectFileGenerator.GenerateProjectFiles (System.String[] Arguments, System.Boolean& bSuccess) [0x00000] in <filename unknown>:0 
  at UnrealBuildTool.UnrealBuildTool.GenerateProjectFiles (UnrealBuildTool.ProjectFileGenerator Generator, System.String[] Arguments) [0x00000] in <filename unknown>:0 
  at UnrealBuildTool.UnrealBuildTool.Main (System.String[] Arguments) [0x00000] in <filename unknown>:0

This, I think, means that …/…/…/…/…/…/…/…/Users/Supraball/Supraball.uproject is incorrect path. Could you try using an absolute path to your project instead of relative path?

Uh great, this at least now stops at another place ; >

./GenerateProjectFiles.sh -project=/Users/SampleProject/SampleProject.uproject -game

Setting up Unreal Engine 4 project files...

Setting up Mono
Discovering modules, targets and source code for game...
UnrealBuildTool Exception: ERROR: Failed to launch compiler to compile assembly from source files 'System.Collections.Generic.List`1[System.String]' (Exception: Compiler failed to produce assembly. Output: '')