I am running Ubuntu 16.04 and Firefox freezes my system about once a day. I know it is Firefox because my system works fine with Chrome. The same freezes occurred when running Firefox from live USB versions of Ubuntu 16.04 and 17.10. When frozen, the keyboard and mouse are unresponsive, and various Ctrl+Alt+ and Alt+SysRq+ combinations (commands on this page for example) don't seem to do anything. I end up having to hard reboot by holding the power button.
I am not a Linux expert, but my understanding is that at this point I should check /var/log/syslog, /var/log/kern.log, and similar files. I have checked the contents of these files, have web-searched the messages, but don't know enough to have any meaningful insights. So what should I do next?
If it helps, below is the end of my /var/log/syslog prior to the crash. And I would be happy to update my post with any more info.
May 7 16:28:41 MyComputer dbus[848]: [system] Activating via systemd: service name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service'
May 7 16:28:41 MyComputer NetworkManager[876]: <info> [1525735721.7446] server identifier 10.239.100.1
May 7 16:28:41 MyComputer NetworkManager[876]: <info> [1525735721.7446] lease time 300
May 7 16:28:41 MyComputer NetworkManager[876]: <info> [1525735721.7446] nameserver '10.239.100.1'
May 7 16:28:41 MyComputer NetworkManager[876]: <info> [1525735721.7446] nameserver '10.239.100.1'
May 7 16:28:41 MyComputer NetworkManager[876]: <info> [1525735721.7446] domain name 'lan'
May 7 16:28:41 MyComputer NetworkManager[876]: <info> [1525735721.7446] dhcp4 (wlp5s0): state changed bound -> bound
May 7 16:28:41 MyComputer systemd[1]: Starting Network Manager Script Dispatcher Service...
May 7 16:28:41 MyComputer dhclient[1352]: bound to 10.239.100.2 -- renewal in 139 seconds.
May 7 16:28:41 MyComputer dbus[848]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher'
May 7 16:28:41 MyComputer systemd[1]: Started Network Manager Script Dispatcher Service.
May 7 16:28:41 MyComputer nm-dispatcher: req:1 'dhcp4-change' [wlp5s0]: new request (1 scripts)
May 7 16:28:41 MyComputer nm-dispatcher: req:1 'dhcp4-change' [wlp5s0]: start running ordered scripts...
May 7 16:29:53 MyComputer wpa_supplicant[1118]: nl80211: send_and_recv->nl_recvmsgs failed: -33
update 1 (May 21 2018)
I am still getting freezes when I run Firefox from a terminal in safe mode with my profile path set to an empty directory (a step suggested by @dsstorefile1):
firefox -safe-mode -profile ~/some_empty_directory/ -no-remote -new-instance
I also ran debsums to check the checksums of the Firefox package, but it did not find any errors.
update 2
I installed Arch Linux on my machine and still got the same behavior. This means it is not a distribution-specific problem.
update 3
I upgraded by RAM, graphics card, and monitor. But the problem is still occurring.
update 4
I updated my BIOS, but the problem is still occurring.