Attempting to view source metadata through the new admin UI generates a stack trace

Steps to reproduce:
1. Ingest the three demo media streams as part of a normal upload ingest. Defaults for everything except for the processing, where you set the default workflow to Hold, rather than publishing immediately
2. Once uploaded, go the the Assets section of the workflow information section, and view one of the /source streams.

Actual Results:
You will see a stack trace that looks a lot like the one attached. This is generated when you view the data for the source stream.

Expected Results:
No stack trace

Workaround (if any):