Form type "&1" is not defined in Customizing

IF &[SWITCH]S4H_DOCU_ON_PREMISE& = 'X'.

What causes this issue?

The form cannot be printed because form type "&V1&" is not defined in
Customizing.

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?

Inform your system administrator.

Procedure for System Administrators

Use the <DS:SIMG.SIMG_CFMENUOLSDFORM>Define forms and print programs</>
activity in Customizing to maintain form type "&V1&" and the
corresponding form name.
ENDIF.

Error message extract from SAP system. Copyright SAP SE.