Occasionally you may have some row failures when importing new contacts (or updating existing contacts) through CSV import. To determine the cause of those failures and make adjustments to clear those failures, follow the process below:
1. Navigate to the 'Contacts' module.
2. Click 'View Import History' under 'More Options' in your left-hand navigation.
3. Click on the relevant import id (this number identifies the batch of contacts you imported. You can determine import by ID, date, File name, # of records, and more).
4. At the bottom of the screen if some rows were considered errors, there will be a downloaded spreadsheet next to "Error Output 1:".
5. Click on 'download' and choose to either open or save the file. Once you've opened the file, the first column in the spreadsheet will explain why the failed row was not imported.