.prel can't find files

I have been using Premiere Elements 14.1 trouble free to create over 50 videos until July 2nd.  I did a long trip to Florida and back, gone for two weeks -- had my Lenovo along, but didn't do any editing.

Upon return home (Pennsylvania), on July 15, PE wouldn't work.  When I tried to load any .prel file -- any one of a hundred -- it asked "where is file XXXX?"  It can't find any of the referenced files.  When I point out where it is, the program crashes.

Using the Geek Squad, I reloaded PE 14 and cleaned up junk files, etc.  That didn't work.  Eventually, we reloaded Windows 10 and I just reinstalled PE -- and everything else.  I've spent 10 days reconstructing my computer.

Same problem.  When I load any project, it asks where the file is.  It's actually in the same place it was when I saved the prel earlier.  When I point that out, the system crashes.

Any suggestions?