Seaquel
SQL Server error code

SQL Server error 4869

SQL Server raises error 4869 at severity 16, which marks a problem with the query or data that you can correct.

The bulk load failed. Unexpected NULL value in data file row %d, column %d. The destination column (%ls) is defined as NOT NULL.
Msg4869
Severity16
Group4000–4999

Source: Database Engine events and errors