Leanplum offers the ability to restore previous versions of A/B tests, Variables or Messages that have been published.
Go to the A/B test, Variables pages or Message that you want to restore. Click on the Previous Versions section at the bottom of the page. Click on the previous version you want to restore, marked by the date and user who published. To the right of the previous version name/date is the restore function - click it.
Your version is now restored.