Guideline could not be applied to &1 on &2

What causes this issue?

The employee &V1& already has a granting for &V2& and it cannot be
changed.
This can have the following causes:
The employee has already exercised awards from this granting
The granting has expired or been forfeited

System Response

The system does not perform any changes for this employee.

How to fix this error?

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

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.