Solution : https://service.sap.com/sap/support/notes/1091248 (SAP Service marketplace login required)
Key words :
sap basis release web, qrfc idoc interface, relevant support package, system issues, error message, wrong status, inbound queue, recognize status 75, correct status, idoc_input_open reason
Related Notes :
| 1004454 | Advance availability of qRFC IDoc interface |
| 817939 | IDoc: IDocs remain in status 75 |