In the latest preview (4.12 P5), I am missing all of the .cpp files for the engine classes. All the headers are there, but no .cpp’s.
I haven’t had a problem with this before, but have recently formatted this machine and installed again. I installed Preview 4 first, then upgraded to Preview 5. As far as I know, neither update provided the .cpp files. I DID check ‘Debug Symbols’ when downloading, but I UNchecked Starter Content and Example Projects.