I have now fixed the 2-3 errors that occurred during the test upgrade run and it runs very well, but at the end when writing the config, an error occurs that cancels the upgrade.
Updating core configuration...
Generating configuration for core (type cmc)...
Configuration Error: Error creating configuration: 'cmk.influxdb'
Could not update core configuration. Aborting.
I have not yet done or configured anything with the influxdb integration.
What can I check/do to eliminate the problem?