Simone, we are using mail gateway, and probably this started after we enabled mail gateway. I am wondering if this could be related to mail (due to "Post" in error message)? Can you provide some background what is this error supposed to mean?
More explanation @Paul:
When the issue occurs, should see if restarting presence or lookup helps. If so - that is the issue and should be sorted. First need to ensure that that is the issue...
Hello!
You can mark it as closed as option. If document is connected with other documents you can not delete it so you will not be able to delete PO, as you will not be able to remove Goods receipt...