Nobody can tell you anything without proper system info and other details, but I'll let you in on a little secret: AE sucks at using MP3 files and your timeline is flooded with them. This is not smart. Convert them to WAV. And then the usual... check your audio config, your footage sources and so on...
I quit the app and found my closest auto-save and used that still lost some work but better than nothing. I still don't get it though its never happened before. I also have a new lead,AE crashed immediately following the blank error:
The crash above is about 2 more hours of work later.