Thanks, @bmv - Yes, I had discovered the mxcf and xcf files were ZIPped archives when I first dug into PEP3. (The icon for the mxcf files was a clue :-D)

I had forgotten about that. The extracted XCF file should work fine with PEPv2.

I'm wondering if there are updated Intel USB chipset driver issues (not Windows 10) that are the root of my problems. I will investigate further to see if I can find previous Intel drivers that may fix my problems ...