After installation QuickRepair must be run once (as you did).
On the bottom page after QuickRepair has gone thru process, Sugar will show differences that has found on some fields in Database.
These differences are updated by clicking "Execute" button.
Once Execute button is pressed, update in Database is made and Drip E-Mail is ready to be used. The Message is really not an Error Message, is part of installation steps.
Let me know of this solves the problem.
Thanks for trying the module. To help you we`d need some more information about your setup.
Could you send us your Sugar diagnastic file or at least which versions of Sugar, PHP and MySQL your are running on?