Since updating Firefox to 140.0 (I am currently on 140.0.2 on macOS Sequoia 15.5), when I launch a Firefox window using the non-default profile, that window is not able to load any pages. When I try to close that window, it either requires me to "force quit" it, or if I wait long enough, the Firefox crash reporter appears. When I first create a new profile, it works. However, after closing that window, or restarting Firefox, the non-default profile can't load pages and eventually crashes. Things I have tried: * Deleting all profiles and re-creating them. * Using new-style profiles instead of the ones managed by `about:profiles`. * Visiting a local address using an IP address to rule out DNS issues. * Starting with the non-default profile (using the new-style profile switcher) * Starting the non-default profile in troubleshooting mode (the browser crashes when trying to restart) * Clearing the startup cache in the non-default profile (the browser crashes when trying to restart)