SAP Message >3700 - Reason for marking as doubtful &1 not maintained

Diagnosis
The reason given for the doubtful entry does not exist.

System Response
You can only adjust an open item (doubtful entry or individual value
adjustment) if you specify a reason for the doubtful entry.

Procedure
Check your entry, or maintain a reason for doubtful entry in
Customizing.
INCLUDE FICA_NA_F5 OBJECT DOKU ID TX