Do you still need a help?
First of all u need to add #define WORLD_EDITOR into gamelib (stDax.h) which is located in the client dir. Then u should include dependencies nad externs, but remember to tick that WorldEditor depends on client libs, next u should run a quick build. Fixing mistakes nad errors: Often std::string was replaced by CFilename, it is easy to fix due to the filename (sz_...). In spite of that when u trigger something.StringPath or sth.NoPath you should rewrite it to CFileNameHelper::NoPath(sth), remembering that sth must be a string type! Of course ::NoPath is just the example so u can easily change it. For more info u should check filename.h, apparentely i don't remember where it is located, u'll have to do a quick research.
Good luck!
@Shogun
This grey error is due to errors with textures(I think). I fixed it by saving my map more often what about debug console?