Acct assgnmt profile &1 period &2 does not exist

What causes this issue?

In the Customizing of posting type 03 (debit G/L account posting), no
entry exists for account assignment profile &V1& in period &V2&.

System Response

If no special entry exists for this event (message 311) in the
Customizing for error events and no basic setting exists either for the
handling of errors with debit G/L account postings (message 300), the
system cannot execute the posting automatically.
Otherwise the system executes the posting in accordance with the setting
for message 311 or 300.

How to fix this error?

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.