ORA-30420
string is not a valid identifier
Cause
All identifiers used in the DBMS_OLAP package must have at most 30 characters, and must start with a letter that is followed by any combination of letters, numerals, and the signs '$', '_', and '#'. Other characters cannot be used in identifiers. The rules for DBMS_OLAP identifiers are the same as for PL/SQL identifiers.
Action
Rename object to conform to the DBMS_OLAP naming rules and try again.