From Source: The game module could not be found

Awh AH! Found the problem!

Because my sources live in a root folder called F:\Sources, the system actually detects the string Source in the path name :

UEBuildTarget.cs CreateModule function:
int SourceIndex = ApplicationOutputPath.IndexOf(Path.DirectorySeparatorChar + “Source”);

So it detects MY root path instead of the project sub folder Source!

So, don’t use the Source string in your root folder!