Your computer was restarted because of a problem? kernel? What's the problem???
Why is my iMac restarting when I shut down?
iMac 21.5", macOS 10.15
Why is my iMac restarting when I shut down?
iMac 21.5", macOS 10.15
That indicates it had a Kernel Panic. If this was the only one, it's likely nothing to be concerned about. However if they continue to occur please post the latest KP report which you can find by doing the following:
Work thru the steps, at > If your Mac restarted because of a problem - Apple Support
Another great tool to help find problems, is > https://apps.apple.com/us/app/etrecheck/id1423715984?mt=12
Your computer was restarted because of a problem? kernel? What's the problem???