Create a new table and try doing select on it. It should give +100 as sql code. If it gives the same error i.e. -904 your database is having some problem. Escalate to your administrator
This is what we did. Hope this is the right answer.
What i did is did a load operation along with image copy, reorg and runstats. Then i find everything set properly.
propable reason for the error could be final updates where not updated in the sysibm catalog tables. once i did a load, reorg and runstats everything was set and the catalog tables also get updatd. This was my understanding.