Hi, David. We had the same problem. We installed the critical update for SP3 and we didn't pass all the steps of the upgrade checklist. The document handling was inactive in 3-tier. After we have found the cause of the problem, we passed through missed steps in checklist and document handling became enabled.
Check both: - Administration \ Setup \ System \ Check lists \ Installation check list - Administration \ Setup \ System \ Check lists \ Upgrade check list Are there any unchecked positions? If they are, you should pass them to get document handling enabled. Pavel