Kolibri stalls during lesson resource management

[lauradanforth]

This is on kolibri-demo.learningequality.org/

Observed behavior

When clicking on "Manage Resources", I'm getting the 'disconnected' notice:

After that, when refreshing the page, I'm getting this page -- clicking "Save Changes" or the X at the top left don't do anything and I need to reload the page make it responsive again.

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Steps to reproduce

While logged in as a coach or admin, try creating a lesson and adding some resources, then going back to manage the resources.

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Context

• Kolibri version - 0.16.2
• Operating system - Mac OS X (using Kolibri-demo BCK instance)
• Browser - Chrome

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[sentry-io]

Sentry Issue: KOLIBRI-FRONTEND-13F0