Dashboard broken after eNewsletter Update

I upgraded the plugin to v. 2.2.3 and was unable to edit previous newsletters—the newsletter would not preview, and clicking in the content area would do nothing. I attempted to create a new newsletter and clicking on the content tab would collapse the entire editing sidebar.

I deactivated and reactivated the plugin and now my whole dashboard throws the white screen of death. I deleted the plugin folder, optimized and repaired all db tables and am still unable to access any page of the dashboard on the site where e-newsletter had been activated.

The front end of the site remains functional and dashboards for other sites on the network appear to be unaffected.

1. How can I go about getting my dashboard back?

2. Any thoughts on getting e-newsletter to work are greatly appreciated.

Thanks in advance for any help!

I have the following related tables in the db: