I had that this morning, don’t worry unless it becomes frequent, it may happen from time to time, in your case, if you just upgraded suddenly this could explain “an unexpected error”.
There is a surprise! So to what level have you upgraded as shown in Settings > About phone > tap on Android version > long press on /e/OS version in order to "Copy to clipboard.
It is an important part of the /e/OS system, very loosely speaking, to avoid direct contact for the user with Google, but still allowing sufficient “filtered” contact to allow the system to run the way it does. Better explained here, microG - What you need to know, A conversation with its developer : Marvin Wißfeld.
If you have upgraded two or more Android versions you may have apps that cannot survive the change, so you should be prepared to have to uninstall one or two if you get indications that they are failing, then install them again after the phone has been restarted.
Quite a few people use the app Cache Cleaner directly after an upgrade to automatically clean the cache of both system apps and user installed apps. Again this would be useful to you if you you have jumped two or more Android versions.