Comment 88 for bug 1798961

This happens to me every week on Ubuntu 16.04. LTS with kernel 4.15.0-112-generic. It seems to be a random complete system freeze. The mouse does not respond, caps lock and numlock do not change light on keyboard, ctrl alt f2/f3/etc does not work, and even Alt + SysRq REISUB does not respond. Only a hard reset works by pressing the power button will reboot the system.

I noticed I could reproduce the bug easily by watching videos and/or reading news on "heavy" newspaper websites in Firefox. In contrast, in Chrome I rarely experience the issue.

From what I have read, and since I have a GeForce GTX graphic card with original NVIDIA drivers installed, I suspect that the problem is strongly related to these three components: video encoder/decoder, browser and graphic card/drivers.