I recently moved my Flarum installation from a subfolder (e.g., example.com/forums) to a subdomain (e.g., forums.example.com). Since making this change, I've been encountering the following error when users attempt to authenticate using OAuth:
FoF\OAuth\Errors\AuthenticationException
Invalid state'
The error seems to originate from the following code snippet in vendor/fof/oauth/src/Controller.php:
if ($e->getMessage() === 'Invalid state' || $e instanceof IdentityProviderException) {
throw new AuthenticationException($e->getMessage());
}
Additionally, I see a detailed error log being generated with server parameters, request attributes, cookies, and query parameters logged as part of the OAuth error handling.
Steps I Took
Moved Flarum from example.com/forums to forums.example.com.
Updated the config.php file to reflect the new URL.
Cleared caches using php flarum cache:clear.
Verified the OAuth credentials in the admin panel.
I suspect this issue might be related to CSRF security due to the Invalid state error, but I'm not sure how to resolve it, I have already tried removing and reinstalling the FoF OAuth extension, but the problem persists
