I moved my app to a different server as part of a rewrite, and forgot to update the URL of the app on Stack Apps. When I tried to send a query to https://stackexchange.com/oauth and pass my (old, incorrect) callback URL to the `redirect_uri` parameter, this is the error I got:

> ##Application Login Failure
> 
> An error occurred while login into an application.
> 
> ###Error Details
> 
> **error description:** Cannot return to provided redirect_uri

I’m still debugging, so I don’t know for sure that that was the issue, but either way, this error message could be a lot more helpful. I don’t know if this is the right place to file a bug/question like this, so I’m happy to post this elsewhere.