Hello,
Thumbs up to Pete's Comment.
Side Effects Analysis is when SEP checks through the ERASER database to determine if there are any other related files, to one already initially detected. The "SEP notification" that appears is effectively ensures that the file in question has denied access, while it verifies the database for more information. There is normally another notification or log which appears after the first one, where it should tell the user what final action was taken on that file, &/or it's related files.
Review the proceeding notifications or logs after the initial SEP Notification, as this will tell you what action has been taken on the detected file. In some cases, you may find that the file in question is either removed, deleted, cleaned or quarantined etc.