The Problem⌗

When trying to complete the OAuth flow for my web app spotifytrack.net, I started getting sent to an error page with a 500 status code and the following unhelpful message:

Oops! Something went wrong, please try again or check out our help area.

The app had been running successfully for years with no changes to the OAuth configuration. The error was easily reproducible just by visiting the /authorize URL directly. It persisted after trying incognito windows, different browsers, different devices, logging out and back in, etc.

Looking at the my service’s logs, it seemed to only be affecting my account; other users were still able to complete the OAuth flow and generate tokens successfully. Maybe other accounts were running into it as well, but I couldn’t easily tell.

The authorize URL I was using looked like this:

https://accounts.spotify.com/authorize?client_id=...&response_type=code&redirect_uri=...&scope=user-top-read&state=

The Fix⌗

The issue was the empty state parameter at the end of the URL.

Spotify’s OAuth /authorize endpoint apparently can’t handle an empty state and returns a 500 error. Setting any non-empty placeholder value for state makes the flow work as expected.

This is definitely a bug on Spotify’s side, but that’s the workaround if you run into it.