The issue occurs in versions of FIMS prior to FIMS 14. You cannot do a grantee change and then void a check. You must first void the check and then do the grantee change.
This makes sense when you think about it since you shouldn't be able to change who the check was paid to after it was paid. But you can void it and then change who to pay. To fix the issue, you need to back out of the void and changes in the backwards order. Usually this means you need to unvoid the check ( the last thing you did) and then do a grantee change to change the grant back to the wrong grantee.
This puts you back where you started. Now you can void the check. At this point you should see an open payable in Open Items. You can then go do a grantee change and then recut the check.