Attempting to remove a trusted location in Firefox crashes the Settings Manager

You can file a bug here:

http://tracker.adobe.com/

The settings manager is it's own process, so I can't think of a reason why the Firefox version would have any bearing on how removing a trusted location works.  It seems more likely that it's either a latent bug and the two are coincidental, or there's a lower-level explanation, like our settings file is corrupted on disk, and the activity of writing and installing the new Firefox version may have resulted in the outcome that causes these symptoms -- but is representative of an underlying problem with the integrity of the filesystem or storage hardware.

Also, if you haven't rebooted since the symptoms began, the old adage "when in doubt, reboot" is always a great place to start... particularly now when system uptimes are measured in weeks and months instead of hours or days.  Computers and operating systems are way more stable these days, but things can still get weird in subtle ways over time.  Actually cold-booting the machine rules out a whole ton of possibilities.

I'll take a look at my Win10 x64 machine to see if I can reproduce this, but we have similar regression tests, and I don't expect that this happens universally.