I have a small server with OAuth2 authentication. In Restfox, I first request a token and copy it to another request (yes, there is a built in flow now ;-)).
The issue happens if I first sent a valid request. Then I restart the server, which discards the old OAuth token.

When resending the previously successful request with the old (and invalid) token, Restfox gets stuck in the "Loading" animation:

After restarting restfox and resending the request, I receive the expected error message:

So, I hope it is not a problem of the server side and my OAuth2 implementation (using .NET8 and https://github.com/openiddict/openiddict-core/ ).

Other error conditions (e.g. "400 bad request" due to invalid parameters) are handled as expected.