Spotify updates its login API regularly. If the config was written for an older version of the site, it will no longer work.
How to recognize a "Hit" (a successful login) versus a "Fail." _Spotify_.svb
Since these files exist to find vulnerable accounts, here is how you can ensure your Spotify account isn't caught in one: Spotify updates its login API regularly
If available for your login method (like via Facebook or Apple), use it. _Spotify_.svb
If you get an email about a "New Login" you don't recognize, change your password immediately and use the "Sign Out Everywhere" feature in your Spotify account settings.