Parallel processing is only supported for Lean Classification.

What causes this issue?

You have entered one of the entity types <LS>CLASSASGN</></> or
<LS>VALUATION</></> for Parallel Processing. The chosen change request
type does not support lean classification.

System Response

Review your change request type configuration.

How to fix this error?

Activate the switch classification flag for this change request type or
choose another change request type.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.