What about add
PublicDependencyModuleNames.AddRange(new string[] {"OnlineSubsystem",
"OnlineSubsystemSteam",
"OnlineSubsystemUtils"
};
to your project build.cs?
Hey, so I have problems with using the OnlineSubsystemUtils in UE4.7.3
When I try to include it in my project, I have to specify the whole path “Runtime/Online/…” even though this path is in the “Source Directories” of my project…
But the real problem occurs when I try to compile, as it seems not to find any paths, even in UE4 itself…
So basically I cannot use it…
Thank you so much! 
Didn’t know that the build file holds dependencies 