I reset the NM database to its default settings and was able to see the Notification Status (empty but no error message).
Then, I restored all my contacts from another AP server that had the same ones and everything is working okay.
How can I delete the entire history of sent notifications (they come from another machine) without deleting all the contacts ?
All AP releases, confirmed in 11.7 and 11.8
To delete the history only:
When there are no sent messages, the file is not even created for the export, so the operation will not put you beyond regular scenarios.
We recommend to store the file for further use, as the upcoming 11.8 will be more resilient to extensive workload and you might want to import the records back again.