Solution : https://service.sap.com/sap/support/notes/325372 (SAP Service marketplace login required)
Key words :
system displays error message 06218 'net price, additional key words me31k, enter net price', required entry field, valid price exists, field ekpo-netpr, item detail screen, price valid, price exists, system behavior
Related Notes :
| 414167 | RM06ENP0 / RM06ENP1 does not transfer any prices |
| 371397 | Printing outlne agreemnt, prce only valid in future |
| 309236 | ME31 Canceling on the condition screen |
| 196446 | ME13 incorrect display of price validity date |