Error : The PRIMARY_SALESREP_ID column in the HZ_CUST_ACCOUNTS table must be null
We upgraded from 11.5.10.2 to 12.1.3 a few months ago and have seen the error "The PRIMARY_SALESREP_ID column in the HZ_CUST_ACCOUNTS table must be null" when amending some customers.
I have seen notes 1556005.1 and 733760.1 which say the primary_salesrep_id has moved from HZ_CUST_ACCOUNTS to HZ_CUST_SITE_USES_ALL.
I have checked these tables and primary_salesrep_id is populated on HZ_CUST_ACCOUNTS but is null on HZ_CUST_SITE_USES_ALL
I am confused by 2 things
1) Why do we not get the error when updating any customer (some update OK, some do not - I have not established a pattern yet)