SAP Note 11294 - Not possible to add number range groups.

Symptom

When you add number range groups, the new intervals are saved, but not the group itself.

Cause and prerequisites

Inconsistency between the table of number range intervals (NRIV) and the (language-specific) table of number range groups (TNRGT). The inconsistency could have arisen due to a transport, for example, in which not all the logically cohesive objects were transported.

Solution
Report RSSNR0T1 returns a list of the inconsistencies. Press F11 = Confirm/Save on the results list and the report restores a consistent status.

Key word: Num range grps