I can't see how this can be an Excel error when Excel is not mentioned anywhere by the OP and also the OP is importing data to SQL Server.

As I said in my earlier reply what worked for me was to play around with those three settings. A few months after this post I started getting another related error for the largest of the source tables. In the end I had to change the insert from a SQL Server Destination / BULK insert to a OLEDB Destination and the source was a select statement (from the same table as before) but with a SET ANSI_WARNINGS OFF at the start. For some reason although the error is in fact a warning, SSIS stops executing the task and logs it as a task error.