Get Rid of Smart List Errors
In your smart campaign, click on Smart List. Get rid of any red squiggly lines that you see.
Get Rid of Flow Errors
In your smart campaign, click on Flow. Remove any red squiggly lines you see by fixing the errors.
Review the Schedule Tab
In the Schedule tab, check Smart List Status for any errors in the smart campaign that needs fixing.
Check Person Restrictions Limit
In the Schedule tab, make sure the number of qualified people does not exceed the person restriction limit.