If u have exception “identifier “FDrawingPolicyRenderState” is undefined”, try Rebuild your project. If it is doesn’t help u, comment out the lines like these from file MyProject.build.cs if u have them and try again:
// MinFilesUsingPrecompiledHeaderOverride = 1;
// bFasterWithoutUnity = true;
PS Maybe someone will help only “Generate Visual Studio project files” also without these lines. (Right click on MyProject.uproject file)
UPD Unfortunately it once eliminates this error. With subsequent compilation, the error will be returned =(