Material Document cancellation not possible

Question

Dear All,
First of all sorry for the long query, it is required to give a clear perspective of the issue.
I am having an issue in which i am not able to reverse the GR which is made on a P.O that P.O is a third party P.O.
I am getting the message "The value of goods movement is negative"
the scenario is as below:-
There are two systems both are SAP system and they belong to the same group of company.The 1st system places an P.O to the 2nd system,then the 2nd system creates a sales order with reference to the P.O and then the sales order in turn creates a PR automatically(as normally happens in third part scenario). That PR gets converted to P.O and the P.O is placed to another vendor which is different from the entire entity.
they have(the 2nd system) placed the order for the material suppose "X" to the outside vendor.
Statistical GR normally happens in 2nd system which triggers a invoice in the 1st system at the same time through an IDOC.( this is only for information)
in this case once the outside vedor has confirmed of the despatch of goods GR made in 2nd system but physicaly the goods have not arrived at 1st system.
now when the goods actually arives at 2nd system they found that the material is sth else than "X" so they didn't made a GR in 1st system and straight away returned the goods.
Now the status of various documents are as below.
P.O of the 1st system--- 1) Invoice has been done equal to the billing amount in 2nd system
                                    2) Invoice reversal has been done for the same amount as above.
Sales order in 2nd system:-1) Invoice or billing has been done.
                                        2) It has been cleared from finance side.( the sales order is in completed ststus)
P.O in 2nd system:- 1) GR done
                              2) Invoice done against GR
                             3) Subsequent debit amounting equal to invoice amount made.
So could some one please let me know first of all whether a GR reversal is required in this case? As the GR is statistical in the 2nd system and the 2nd system is not actually receiving any goods.
If yes then what is the meaning of the messge given in the begining?
I tried to reverse some other P.Os for the same material which are having GR and IR on a trail basis and i am able to do without any error.
If the material valuation is going negative then it should happen to all?
Thanks for your patience in going through the long query and sending a reply.
Regards,
Sushanta

Answer 1

Have you change the PO price in another goods receipt and after that made a goods receipt reversal? I got this message when we did a goods receipt with a PO price and the good reversal with a different PO price. The system acumulate the variance and one time they do not allow you to do the goods reversal because you get negative.
regards