Reservation document cannot be deleted

What causes this issue?

The material reservation document cannot be deleted because it is
integrated with Funds Management (FM).

System Response

The material reservation cannot be deleted.

How to fix this error?

You can set the deletion indicator in the document line item.

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.