When clicking into the Online Express plugin after enabling Consent Tracking, users notice that Online Express will automatically attempt to add opt-out Consent records into the Raiser's Edge database and then generate the error "An item with the same key has already been added".
This was resolved in the 5/1/2018 update of Online Express. If you are still experiencing this error after 5/1/2018, please contact Support.
Steps to Duplicate
Log into RE with any RE Username
Click on the Online Express plugin
Notice the "Updating.....Adding opt-out consents to records" prompt