At some point while in the editor, the community packages section stopped loading regardless of the game I was editing. I tried the following steps to resolve the issue without success:
Quitting Crayta and playing another game on Stadia for five minutes, then returning to Crayta
Shutting down Stadia completely for 30 minutes and then returning to Crayta
Quitting Stadia, returning to Stadia, and playing a different game on Stadia for two hours, and then returning to Crayta
Eventually I shut down Stadia for the night. When I returned this morning, the community packages tab was functional again.