Webapp should show a user-facing error when the backend returns 502 Bad Gateway #873
Description
Describe the bug
Originally reported in #871: when the API server was unreachable and the reverse proxy was returning a 502 error, the frontend was just showing an infinite loading spinner. It should show an error to the user instead. I'm guessing that this probably affects all 5xx error codes, not just 502.
Changeset URL
No response
Environment
any
Additional information
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