It is a related table populated automatically with default settings, so you are using it even if set to none, if you read me posts and do as requested it would help narrow it down but you seem reluctant to do this so I will presume you imported them and did not populate related tables as AX would do if you manually created the record and therefore you caused your own issue.
Why is because you imported your customers without populating all required tables in my opinion, but you seem to have ignored this question a couple of times.
The error “Must be a number between 1 and 999.” is due to the credit card - number of days before expired not beeing filled. (Sales ledger parameters) This error does not mean anything unless you are using the creadit card setup.