This entry does not support navigation to maintenance application

What causes this issue?

The selected entry does not support navigation to the maintenance
application in which the entry data can be maintained.
Reasons for this can be:
The entry belongs to a namespace for which no application handler has
been registered.
The handler does not support navigation for this entry.

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.