Cannot cancel a PO

 When trying to cancel a PO get the following error messageUnable To Cancel Purchase Orders Due to Error Please Undo Changes In The Current Document Revision.

If we open the PO and make change to the PO t and try to approve it again the status change from Requires Reapproval to In Process not approved and there is no control action that we can perform. We than reject the PO and the status change to requires re-approval  and on the control action the cancel po action is available but we get the error message. We want to cancel the PO for the requisition can go back to Autocreate and the buyer will than create a new PO.