I did not detect the same problem prior to the conversion, however I did not fully utilize OC at that time as I knew a conversion was pending.  It was only tested a couple of times, but I don't believe the problem existed.  I understand the conversion is from ANSI to UNICODE format.  I do not have the option of reverting to ANSI format.
I have tried a couple of different primary key settings statements, including a simple "Select "1'"" in order to test with a single record.  The current statement is "Select newid()".  I have also used "select hash(now())".  The same error consistently occurs.
The primary key is assigned to object_id.  The other two mandatory keys are owner_id and object_type, select ("david") and select("object") respectively.