User-defined text has a long text; changes cannot be made to text type &

What causes this issue?

The existing user-defined text type has been changed to a user-defined
text type for which the <LS>Document</> indicator is set in the IMG
activity <LS>Specify Types for User-Defined Texts</>. This user-defined
text type is thus linked to the document management system and cannot
therefore contain a long text.
Since this user-defined text has a long text, the text type cannot be
changed.

System Response

INCLUDE EHS_NA_NO_MAINTAIN OBJECT DOKU ID TX

How to fix this error?

If you do not require the user-defined text with a long text, delete
the old user-defined text and create a new user-defined text with the
required user-defined text type.

Error message extract from SAP system. Copyright SAP SE.