Hi Bart,
It seems the value you are providing for Division (y) can’t be found in the list of available divisions (called “partitions” in Invantive software).
You can check the list of divisions (in the table ExactOnlineREST..SystemDivisions and systempartitions@datadictionary) and check whether the division is visible there.
If not, the user doesn’t have access permission on the division (for a possible reason see Forbidden - User division is not within division scope (Itgeneor228 / itgenoda060) - 2 van forums), or the division doesn’t exist.