After you've added all of your campaign steps, the red Errors tab will automatically display if there are any issues that prevent your campaign having a valid flow (i.e., there is something that will prevent a contact being able to move on to the next step).
To view any campaign errors:
- While managing a campaign, click the gear icon (if you haven't yet saved your campaign, click Save; the gear icon is only available after the first save).
- Click the red Errors tab at the bottom-right of the dialog.
After all errors have been resolved, this tab will no longer display.