Kernel panic not syncing timeout not all cpus entered broadcast exception handler

It started doing this after I installed 157, but not until I rebooted it.

Kernel panic - not syncing: Timeout: Not all CPUs entered broadcast exception handler

I read online and this seems to be related tot he processor C States. I tried enabling Watchdog in the BIOS, but it kept getting false triggers. I do have the option in the BIOS for “Max C State 3”, currently disabled. Not sure if that will help in this case.

The long leading gap, the firewall was down. then yout se the frequent reboots after I enabled Watchdog in the BIOS. The final, longer gap is where I disabled Watchdog, it has been running fine ever since. (but may crap out later, who knows? it’s done this 4 times since Sunday Evening)

The CPU is older, but the Mobo and all the other internals are 7 months to a year old.