So I tried to open a project that I downloaded and it says that some modules are missing. I pressed to rebuild it. And now it says “try rebuilding from source manually”. So I opened it in the visual studio, tried to build it and I got this error. I read some other threads and I couldn’t find solution for that. I must say that I’m new to UE and I will be thankful if someone will help me.
Right-click the .uproject and select ‘Generate Visual Studio project files’
I did that. And then I tried to rebuild it in VisualStudio and got this error which I attached.
Can someone help?
Hi DzikusToJa,
You need to declare the LogGameMode category in SCoopGameMode.cpp or include the header file that does that declare.
If you can declare the category as DEFINE_LOG_CATEGORY_STATIC(LogGameMode, Log, All) in CPP.
Hope that helps. Cheers,
I to had this issue 
BUT…I fixed it by looking at the Log when it attempts to rebuild the project.
The bottom line gave me the answer, I had to install Windows SDK v8.1 in order for it to successfully rebuild the project.
Link: Windows SDK archive - Windows app development
Just install this (make sure all the boxes are checked), Open the project, Click “Yes” when the error appears and it will build and open the project editor.
Hope this helped 