Export To File Issues

This is almost certainly one of 2 things, Selection and/or Routing.
 
You must ensure your route all of your tracks to a Master Bus (which YOU have to insert). If you use other busses to group like instruments together, these too must go to the Master Buss
 
If you mute your Master bus you should hear silence. If not investigate and rectify.
 
Selection. Either select ALL (ctrl + a) or select NONE (ctrl + shift + a). I prefer the latter.
 
Select File> Export.
Under Source Category choose Main Outs
you said you wanted a wav so select Stereo (Channel Format), 44100 (Sample Rate), 16 (Bit Depth), None (Dithering)
 
Tick all the other boxes.
 
Hit Export and choose a location for the wav.
 
If necessary, sweep in the timeline to select the exact length you want exported.
 
That's it, takes much longer to type it than do it.

Thanks for the reply, all of the routes are going to the master buss. I have about maybe 39 tracks and 6 busses. The 39 tracks are routed to either of the busses and the busses are routed to the master buss. Now, like I said it doesn't happen all the time, but maybe 4/10 times I can expect a non audio file to be exported. Then I'll have to try and try until it finally works, and I never change anything about the project, I just keep trying to export. Also, when I say file--it's a blank white file folder that exports, not your typical windows audio file look.