Hi HenryGR, Thank you for your question. Please make sure in both profiles that the extensions are up to date: [[Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems]] Also let's start here for general hanging, even though it may have to do with a process happening there: [https://support.mozilla.org/en-US/kb/firefox-hangs-or-not-responding#w_firefox-hangs-when-you-quit-it] What are the results after these troubleshooting steps?