Reference field &1 does not exist in the dynpro or has an incorrect type

What causes this issue?

You are processing a pushbutton for dialog help and have entered a
reference field to which the help should refer.
This reference fields does exist, but not in this screen, or it has in
correct type. Only input/output fields and frames are allowed.

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.