Someone far more intelligent than me could probably answer this better but at a guess from looking at that log the build is failing. Have you tried hitting the ‘build’ button in the editor to see if you get the same error?
Seems it points to this being the problem:
LogPlayLevel: InternalUtils.SafeCopyFile: WARNING: SafeCopyFile Exception was Exception in mscorlib: Le fichier ‘C:\Program Files (x86)\Unreal Engine\4.11\Engine\Binaries\Win64\UE4Game.pdb’ est introuvable.
LogPlayLevel: Stacktrace: à System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
Which after having to translate a few key words into English says the file cannot be found, is that path valid?, I notice it’s got (x86) in it but you’re building to a 64bit target by the look of the path, not sure if that’s relevant just something I noticed.
Also this might be completely irrelevant but just looking at other error messages to do with mscorlib, have you got .net installed on your machine?