Document categories and sequence and assignment of bank statement

 Hello,

I create a category with the BANK ACCOUNT NAME,and define sequence and assign to category.

When i am importing bank statement, the error appear DOCUMENT SEQUENCE IS NOT DEFINE.

Why it is now showing error?

I attach correct table for cash management application in category window and keep same date on sequence window and assign window.

The first question is system doesn't create category automatically for bank account?If not,what should be enter in CODE field of document category?I enter BANK ACCOUNT NAME