Hi Chuck,
Running PM 28.9.3. FEBE 10.4, Win 7
The last few times I've run FEBE in PM 28.9.x, it has seemed to hang at points along the way. A couple of times, it hung at about 94% completion and I aborted FEBE's backup. The backup itself seems complete and intact.
Today, I got the famous "Unresponsive Script" message indicating the location chrome://febe/content/febe.js:8185. So I wonder whether recent updates to PM might be causing a bit of a problem with FEBE 10.4. Have you received any other inquiries in this regard?
Thanks,
Elchanan