Autosave Corrupt or damaged

You need to delete the autosave file, the location of this file depends on the version of PSP & windows you have;
Autosave file corrupt?

It depends on your version of PSP and version of Windows where it is, try here;

Mine is PSP9 and Vista and it is in
C:\Users\Me\AppData\Local\Temp\Temp Files
Or it could be
C:\Users\Me\AppData\Roaming\Jasc Software Inc\Paint Shop Pro 9\Cache
Coral has XP and PSP8, it is at
C:\Documents and Settings\Me\Local Settings\Temp\Temp Files

The autosave data is stored in your temp files path (go to file->preferences->file locations and read the location from the "Undo/Temporary Files" location. Autosave data consists of an .ats file that PSP uses to reopen things, and a PSP file for each of your open files. You can start by deleting the .ats file - that will let PSP open normally. Now try opening the PSP files via the browser or file->open. Likely only one of them got corrupted by the freeze, or if you are lucky it was just the .ats file that is corrupt and all of your images are still safe. Once you have everything recovered just delete the psp files from the temp directory