Cannot login with Administrator after Couchbase 4.5 online upgrade

I ran into an issue after upgrading to Couchbase 4.5 for Enterprise. While doing the upgrade I was able to join 4.5 nodes to the existing 4.0 nodes in the cluster and access the admin page after joining. However, now that all of the nodes have been transferred over to 4.5 and the upgrade is complete, the Administrator user no longer works through the UI and I keep getting a “Login Failed. Try again.” message.

Running command line tools (e.g. cbq) using the Administrator user and passwords works no problem on the 4.5 nodes.

Is there an issue with the 4.5 UI after an online upgrade? Do I need to run the command line tool to reset the password for the UI to work again?