You cannot use fct &1 as a check function as it contains no exceptions

What causes this issue?

Function module &V1& you want to use as a check function does not
contain any exceptions.
However, a check function must contain at least one exception that is
returned when a user enters invalid input values.

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?

Proceed as follows according to your requirements:
Use a different function module.
Define at least one exception for function module &V1& (see Customizing
for <LS>Process Management</>).

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.