Solution : https://service.sap.com/sap/support/notes/75947 (SAP Service marketplace login required)
Key words :
additional key words activity type, maintenance orders' solution maintain, proposal maintenance activity type, affected order type, error message nr751, correct error message, object order' appears, 'number range interval &2, correct customizing settings, 'order type &
Related Notes :
| 179153 | NR751: "..number range interval &3 does not exist." |