Greetings, giles176.
Since your Mac restarted because of a problem, consult the following steps:
“Check your softwareIf the issue is caused by software on your Mac, one of these steps might help:Install all available software updates.If your Mac suspects that a particular app caused the restart, it might ask whether you would like to move the app to the Trash. Click Move to Trash, then contact the software developer to see if a software update is available.Use safe mode to try to isolate the cause of the issue.Reinstall macOS. If the issue continues after reinstalling macOS, check your hardware.
Check your hardware
Learn how to check your connected devices and other hardware.Check peripheral devices firstIf you don't have any devices attached to your Mac, skip to the next section.Shut down your Mac.Disconnect all peripheral devices, such as hard drives or printers. If you have a desktop Mac, make sure that only a display, keyboard, and mouse or trackpad are connected.Turn on your Mac.Use your Mac for the amount of time that it would usually take for an unexpected restart to occur.If an unexpected restart occurs, follow the steps to check the internal RAM and third-party hardware.If an unexpected restart doesn't occur, turn off the Mac and connect one peripheral device at a time until an unexpected restart occurs.Check RAM and third-party hardwareCertain models of Mac computers have removable memory (RAM). If you recently installed memory or a hard disk (or SSD), make sure that it's compatible and installed correctly. If possible, remove it and test with the original memory or disk.” If your Mac restarted because of a problem
We hope this helps!
Sincerely.
