Seaquel
SQL Server error code

SQL Server error 6225

SQL Server raises error 6225 at severity 16, which marks a problem with the query or data that you can correct.

Type "%.*ls.%.*ls" is marked for native serialization, but field "%.*ls" of type "%.*ls.%.*ls" is of type "%.*ls.%.*ls" which is a non-value type. Native serialization types can only have fields of blittable types. If you wish to have a field of any other type, consider using different kind of serialization format, such as User Defined Serialization.
Msg6225
Severity16
Group6000–6999

Source: Database Engine events and errors