Writer crashed and didn't recover autosave, though autosave was setup for every 15 minutes. Any ideas?

I’m running LibreOffice and OS X 10.10. I lost 3.5 hours of work.

I’m find it in

Have a look into the backup folder you will see the location at your PC when you look into:
Tools > options > LibreOffice > paths > backups.
You might find your document.

What Can I do if it’s not there?