"Examples: End of line format changing (CR vs CRLF), "NULL" appearing in numeric columns, delimiters changing (e.g. normally a pipe, but occasionally appear as commas instead)." If with Changes within the same file you are in a problem.

One possible solution is may to use bulk insert into a staging table with one column varchar(max).

In that cloumn you can test for certain conditions for each row in the text file with SQL statements

and then split the row into the apropriate number of columns and insert in a useable table.

I use this typ of procedeure then I import text files.

Best regards