FJK

Thank you, @rakeshsejwal ?

I appreciate your chiming in! In fact, I have no doubt the issue to which you alluded is somehow related.

Mine is indeed a Mac, and I am afraid I have no Windows 10 machine with which to test just at present… As far as I know, there is only one way to quit Firefox on the Mac, and that is using File → Quit or ⌘-Q — or any other shortcut that results in the same command being sent. In that light, I cannot say that I have tried various ways of quitting Firefox beyond the official and obvious.

Thank you, nukecad. for chiming in! ? I find it interesting that your results vary, as I can reproduce this pretty consistently… I did delete the Site Preferences in my testing, which may explain the discrepancy. I haven’t narrowed down my analysis to the one checkbox that might trigger the hang — only to the general “clear all” operation — and I am afraid I cannot afford to mess up my Firefox install yet again just now. There may also be a Mac vs. Windows issue at play, although Firefox is pretty consistent by design. ? I do not think that external apps like CCleaner could cause a hang in this case, as they should only kick in after Firefox has quit, and not while it hangs trying to do so. Of course, such and app may corrupt things and prevent the extension from restarting properly, but I do not think it could interfere with the shutdown process per se. In any case, I am not using CCleaner, or anything similar, on this machine. ? What do you think? ?

Dear all, I believe I have found a sadly reproducible hang using either the latest version of Firefox or Firefox Developer Edition. Whenever the Malwarebytes extension is installed and Firefox is set up to clear its caches, cookies, and all site data on quit, the quitting process hangs. All that is required is to install the Malwarebytes extension and load its preferences before quitting Firefox. Simply installing the extension without having a look at the settings page does not seem to trigger the issue as reliably for me. From this point onwards, any time Firefox is quit, it will hang, presumably while attempting to clean the contents of the user’s profile and something owned by Malwarebytes. Note that I was able to reproduce it on clean installs of both Firefox and Firefox Developer Edition with no other configuration changes and no other extensions, plug-ins, or themes installed. Is anyone else seeing this?

The domain circule -dot- cc is currently blocked by the new Malwarebytes Browser Extension due to “Possible Suspicious activity.” As the administrator of this site, I can confirm there is nothing suspicious or malicious about this domain, which only hosts a few static HTML pages. The IP addresses are 208.94.116.183 and 2607:ff18:80::e7e.