Missing Airports

I was trying to load some new gates into CYYZ. When I saved the new AFCAD file and went into FS2002, something strange happened. The airport name shows up but I can't select any gates or runways and I wont even go to the airport. The same thing has happened to Toronto Downsview since I tried to load the new Pearson gates. The airport is still physically there. What's going on and how do I fix this?