Answer
This points to a problem with an Oracle domain/extensible index (the kind built on Oracle Text or a similar indextype) rather than an application-logic issue — ODCIINDEXUPDATE is the internal Oracle callback used to keep that kind of index synchronized as underlying data changes, and background tasks touching indexed rows can fail if that index has become corrupted or is in a bad state. Dropping and recreating the specific index involved has resolved this for confirmed cases — this is the same general category of issue as a domain index reported as LOADING/FAILED/UNUSABLE, just surfacing through a background-task failure instead of a direct error on the indexed screen itself.