Theres this big map that i have been working on, and everytime I've been loading it up, it loads just fine, but now when I load it up, all my brushes are gone. The only thing that shows is my patches that I made, and all my brush work that was made into enities. What could have caused this to happen, and how can i fix it.
Go into your base/maps folder, and move your .map file somewhere else (temporarily). Rename the .bak file with a .map extension, and try to open it in Radiant.
If that fails, you'll need to open the map file in wordpad and read the code line-by-line to see where the problem is. Chances are, it's at the beginning, because you said you have no brushes at all. Can you post the first 30-40 lines?