This error occurred when a new DME and payment method were created but I don't see anything in the setup that would cause this the error. Do you think copying an existing DME file or OBPM* configuration would have caused this reset? I've done this many times in the past without error....
When this is setup the local payment program (in the netherlands) can have 7 document's. An other way is to say that you want to pay all the lines. For this you set in the vendor master data de Indicator: Pay all items separately (tab). In the posting you fill in the field text...