Create a data processing function module.

What causes this issue?

You have called the function for editing view contents. The function
modules needed for the maintenance functionality of this view are not
available in the system.

System Response

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

How to fix this error?

The data processing function module must be re-generated.
INCLUDE 'NA_SYSTEMVERWALTUNG' OBJECT DOKU ID TX

Error message extract from SAP system. Copyright SAP SE.