If you happen to get an error “The value violated the integrity constraints for the column”, it means that it tried to insert null value into the non nullable column in the database. If the source is table or in any other easily verifiable format, you can visually look at it. If the source is Excel, it is a bit tricky.
When the source data comes from Excel file and you get this error, it means that either blank rows exists somewhere in the middle of data or at the very end. Even though visually you will not be able to verify if the blank rows exists in Excel or not, try to select all the blank rows all the way upto the last Excel row, right click on the selection and press “Delete” to delete it, save the file and rerun the SSIS package again.
Hopefully this would solve your problem.