Invalid factory calendar or error in the factory calendar &

What causes this issue?

This problem is caused by a setting error.

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?

Check the various periods of the factory calendar in customizing. If
you do not have the necessary authorization to do this, inform your
system administrator.

Error message extract from SAP system. Copyright SAP SE.