RDM Crashes on Prompt to Install Add-ons

We're deploying RDM 8.0.12 with a custom installer that includes a SQL server data source. On the first connection to the data source, users are prompted to install the necessary add-ons for the DB's sessions. When they click the button to begin the install, RDM crashes. When the application restarts, the Navigation pane is not visible and has to be re-checked in the View menu. This crash-restart-no navigation issue repeats any time we add a new type of session to the SQL data source that requires a new add-on be installed. This has happened with both Windows 7 and Windows 8 machines, all 64-bit.