The system creates intervals dynamically

What causes this issue?

For dynamic interval creation, the system does not determine the
intervals until the mass run is started, since the necessary data is not
available until this point.
You cannot change the interval distribution manually in this case.

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.