Line layout variant & is not defined

What causes this issue?

The entered line layout variant is not defined.

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?

Please check whether you specified a valid line layout variant.
You receive the list of the line layout variants in the Financial
Accounting configuration menu.
IF &DEVICE& = 'SCREEN'
<DS:TRAN.OBO1>Proceed</>
ENDIF

Error message extract from SAP system. Copyright SAP SE.