I came across this issue at a customer site recently where they were having problems with the VMM management pack. A deep dive into their SCOM logs showed 31553 errors with a description of error converting IDENTITY to data type INT.
This isn’t a common error, but it is not unknown either. The most relative posting on it that I could find was from Marnix Wolf here.
We checked the ManagedEntity table, and as expected saw the max value listed, but when we reseeded it, the problems persisted. As it turns out, there are two other tables that can cause this as well. The “ManagedEntityProperty” table and the “ManagedEntityManagementGroup” table. In my case, one of these had also maxed out its identities. Once we reseed that, everything was running smooth again. The process for reseeding the tables was no different than the one Marnix defined.