Useful information to include:

• Minecraft version 1.16.5 forge-1.16.5-36.1.2
• CC: Tweaked version - cc-tweaked-1.16.4-1.95.3
• Logs: Stacktrace from lockup- https://gist.github.com/ProsperCraft/ea7066b285507d7710b8eb1e461f4585

A player had just copied this code in and had the turtles mining for about 15 mins - https://pastebin.com/rpXRAZs4

From this website- https://www.computercraft.info/forums2/index.php?/topic/5681-variable-size-quarry-now-with-super-ore-quarry%e2%84%a2/

Was there anything else going on on the server at the time? I can't see anything especially worrying in CC's stack threads.

Rather annoying that the main server thread doesn't appear within that crash at all. I don't suppose you still have the full logs?

Here are the full debug logs - https://gist.githubusercontent.com/ProsperCraft/f03454c56fbe6a070060ea53dc4cc169/raw/65f0c7ff6c66fb06c4217a6e751312294ee061e8/gistfile1.txt

We had this crash an hour before - AppliedEnergistics/Applied-Energistics-2#5158

Are you sure those are the right logs? That ends with the same CME crash as the AE bug you've linked above.

More investigation shows that the server discord link never showed the server going down and coming up between the AE2 crash and the hard lockup, so it must have crashed and not rebooted, then the watchdog kicked in and rebooted the server.