Attempt to bulk copy a null value into a server column that does not accept null values.
This error occurs when you attempt to bulk copy a null value into a table column that does not accept null values. This most often occurs when the column is changed from NULL to NOT NULL after previous bulk copies.
If the source file being bulk copied is character data, the file can be edited and the column value changed to an appropriate value for the column definition. You can also change the current definition of the table or create a separate table with a column definition that allows null values.