Seaquel
SQL Server error code

SQL Server error 6958

SQL Server raises error 6958 at severity 16, which marks a problem with the query or data that you can correct.

Invalid definition for type '%s'. An 'all' group may not appear as the child or parent of any other model group, it must have minOccurs = maxOccurs = 1, its child elements must have maxOccurs = 1
Msg6958
Severity16
Group6000–6999

Source: Database Engine events and errors