Adobe Audition Crashing

Having seen the size of your temp file, that the reason for the 'crash' is because you've exceeded the 4 Gigabyte wav file limit. You can't exceed this because that's the size limit that a 32-bit unsigned int can write to. There's nothing you can do with a temp file - changing its extension makes no difference, especially to .sesx. That extension only applies to Multitrack sessions, and not Waveform recordings at all. There is no 'automatic backup' of anything to do with Waveform recordings, and indeed we don't recommend that you use Waveform at all, especially for recordings of any length, where the file size is going to be a significant issue. So, I'm afraid your file is effectively lost - we have no means of recovering temp files.

If you want to make recordings that long, then really, you should use proper logging software, which gets around this issue by writing direct to file and automatically starting a new one when the size limit is reached. Or, if you insist on using Audition, then remember to stop and start a new recording before getting to the file size limit. And record in Multitrack view - it writes direct to file and if there is any problem, the files are recoverable, unlike the temp files that Waveform records to.