Seaquel
SQL Server error code

SQL Server error 7961

SQL Server raises error 7961 at severity 16, which marks a problem with the query or data that you can correct.

Object ID %d, index ID %d, partition ID %I64d, alloc unit ID %I64d (type %.*ls) , page ID %S_PGID, row ID %d. Column '%.*ls' is a var column with a NULL value and non-zero data length
Msg7961
Severity16
Group7000–7999

Source: Database Engine events and errors