Click the Import button to begin actually importing the data. A progress bar will display the progress of the import, and the number of records added, updated, or skipped will be displayed. Additionally, a count of the number of warnings or errors will be displayed. A warning is considered a non-critical problem (e.g. a field is too long and will be truncated), while an error is a critical problem that will result in the record being skipped (e.g. a key field was left blank).
Either wait for the import to complete, or if there are already numerous warnings or errors indicated then click the Cancel button to cancel the import. Normally, cancelling the import will automatically undo all database updates that have been processed so far. However, if rollback protection has been disabled then cancelling the import will not undo the database updates that have already been made (see import option “Disable Rollback Protection” under Standard Import Options).