Message: "Error: AQL: internal error - in index"

When any error containing Error: AQL: internal error - in index is shown after any main action after upgrade (for example after Unloading snapshot or starting Network discovery).

The database got corrupted (no worries all of your data are safely stored) and is necessary to run maintenance.

This can be done in Settings → Advanced → System in the main GUI. For more information see https://ipfabric.atlassian.net/wiki/spaces/ND/pages/2830008344

If this does not help, we recommend restarting ArangoDB process in System Administration (port 8443) https://ipfabric.atlassian.net/wiki/spaces/ND/pages/1899823108 and running maintenance - see the previous step