Hi, I have had many successful years using Firefox until 4 days ago. I uninstalled Firefox in order to remedy a recurring missing bookmarks issue. * I used the 'full' version to re-install - install proceeded to around 50% then crashed my system. * I uninstalled the remnants and tried to install using the 'stub' installer, it crashed immediately * I uninstalled all anti-virus software, this time the full installer ran all the way through but when I clicked on Launch Firefox, my system crashed again. * After each crash, the system restarted and remains stable, nothing else appears to be affected. * Basic diagnostics, returns no violations * Each crash returns - stop code: Critical_process_died (0xEF) * my Win 11 version 24H2 osb 26100.7462, FireFox version 146 any ideas ?