Error Upgrading NAV 2013 R2 to NAV 2016 (Object Name already exists table 2000000069)

Converting NAV 2013 R2 Database to NAV 2016 gives an error "Object Name already exists" and can't rename Client Add-in to Add-in. (Both Names seem to exist in SQL).

I have tried deleting both tables, and entries in Object, Object metadata, etc., but nothing seems to work.

Any suggestions?

Thanks in advance,
Bill