This looks like some of the tables are not there for this monitored instance. It would perhaps be best to enter a support case on this one. If the schema isn't correct however you maybe able to have DPA correct the missing tables.
go to options -> support tab -> Database query tool
Run select ID, NAME, MONDBVERSION from COND where name = '<your server name>'
Validate that in this table the ID is in fact 2
Then if this looks correct append stop the monitor and .0 to the end of the MONDBVERSION for an Oracle repo I would be something run in the query window like this update cond set MONDBVERSION = MONDBVERSION || '.0' where ID = 2;
As an example this would change '126.96.36.199.0' to '188.8.131.52.0.0' which is enough for DPA to think it has changed. After the upgrade logic runs, the version will be set back to the real version.
Restart the monitor and then check it the issue is still present. If so open a support case.