On ./GenerateFiles.sh , I run into these errors. This occurs on 4.5 and 4.5.0-release github branches xbuild Source/Programs/UnrealBuildTool/UnrealBuildTool_Mono.csproj /verbosity:quiet /nologo /p:TargetFrameworkVersion=v4.0 /p:Configuration=Development /usr/lib/mono/4.5/Microsoft.Common.targets…

If Engine/Binaries/DotNET is empty, you miss the third party libraries. Extract Optional.zip, Required 1of2 and Required 2of2 into the root directory, and start GenerateProjectFiles.sh again.