I try opening an autos-save version of something I'm working on.  I get a message that it will not open or may be incompatible with my Sonae version  ...  Sonar Producer X3e.  I have been manually saving the file as well but can not find it on my Hard Drive.   Has anybody else out there had this problem that has a suggestion as to what I might do to retrieve my work?   

Try a reboot. Those files should be there and they should load. Something else could be causing problems.

Having used computers for a number of years, I've adopted the tried and true method of saving often.  That also means using Save As to save versions as I progress along.  I'm never more than a click away from winding back to something I had recently.
 
Things can go wrong with any computer file.  It's funny how it especially seems to happen to the important ones.