Appointments+ makes site go blank when activated

Hi, I had the Appointments+ plugin working fine on my site when it lived on Webfaction. We recently used BackupBuddy to move it to EC2 while we look for a new hosting provider. The Appointments+ plugin now makes the entire site come up blank (including the admin interface). I had to go in via SSH and delete the /wp-content/plugins/appointments dir to get the site to come back.

Any suggestions on how to troubleshoot this? I'm assuming somewhere there is now a hardcoded filepath reference that lives in either the db or the code which needs to be manually updated. Reinstalling the plugin unfortunately does not fix the issue. thx

PS. the form to submit this question would not let me select the Appointments+ plugin for some reason so this is inappropriately tagged as WPMU Dashboard for now