Plant & not defined (please check your input)

INCLUDE NA_WERK_UNDEF LANGUAGE EN
<DS:SIMG.SIMG_CFMENUSAPCOX10>Define, copy, delete, check plant</>

What causes this issue?

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

System Response

How to fix this error?

Please check your input. If necessary, contact your system
administrator.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.