Solution : https://service.sap.com/sap/support/notes/154855 (SAP Service marketplace login required)
Key words :
symptom account assignment category 'u', user-specific account assignment category, additional key words contract, account assignment category, contractcreate purchase order, purchase order, contract item, consumption posting, selection screen, program error
Related Notes :
329161 | Error message 06062 for contract release order |
170403 | ME21 IR indicator not copied from PReq |