Function module &1 is discontinued; see comments in its source code

What causes this issue?

This function module is no longer used. The source code of the function
module contains comments that explain why this was necessary and how you
are to perform the tasks for which the function module was developed.
Had there been a replacement function module, you would have been
informed about this by another message.

System Response

The system does not allow you to call this function module. If it is
still possible to call the function module, this requires both technical
competence and additional authorizations.

How to fix this error?

If you are an end-user and not a part of the technical IT team, you
probably do not have access to the source code. Contact your IT support
team for assistance.

Procedure for System Administrators

You must replace this function module in all your solutions.

Error message extract from SAP system. Copyright SAP SE.