Flyover 2.0 - GitHub Authentication not working

Hi Shade, thank you very much for your awesome plugin!

I have set up a GitHub App for authentication and tried it out.
Unfortunately the only answer I get is:

Fatal error: Uncaught TypeError: Argument 1 passed to Flyover\User\Userload() must be of the type array, boolean given, called in /www/htdocs/w0189554/forums.prydeworx.com/flyover.php on line 443 and defined in /www/htdocs/w0189554/forums.prydeworx.com/flyover/User/User.php:34 Stack trace: /www/htdocs/w0189554/forums.prydeworx.com/flyover.php(443): Flyover\User\User->load(false) #1 {main} thrown in /www/htdocs/w0189554/forums.prydeworx.com/flyover/User/User.php on line 34

The problem is, that the array $accounts is empty, and reset($accounts) then returns false. This condition isn't questioned, only whether the count is greater than 1 or not. In this case it is zero.

I tried with my GitHub credentials and with a wrong password, and tested with plain and extended redirect URI.

What could be the issue here?

No, no blank spaces. I had a look in the database, no user registered, yet.
So it seems that flyover.php:112 $flyover->user->register(...) failed. The resulting $attempt then is empty.
However, this method calls $userhandler->insert_user(), which always returns a valid array, at least as far as I can see and unless it throws, which would be caught and handed over to inline_error().

I am completely at sea... Maybe some options I set in MyBB jeopardize this. I'll play around with the settings...

I would ask you a temporary FTP account to look directly into the issue if you don't mind. Since you don't hold a Discord account, you can send the details over Private Messages here on MyBBoost. Everything is, needless to say, confidential.

I will add one for you.

*sigh* I have no idea what I can do.

I have:
1. Disabled all plugins and cleared all caches, then enabled Flyover only.
--> No success
2. Added GitLab support.
--> Same error

I'll PM you when I have an account for you.

Thanks alot for your help!

Thanks to @Yamakuzure who let me test directly on his forum, I have traced down the issue to the fast registration option, which is not working and breaking the login flow. While this does not pose any security risk, the option must be disabled in 2.0 to let the plugin work. This little, but seldom used functionality will be restored in a future update.

Thanks to Shade everything works fine now!
I have "Whisper" installed, and the option in question is listed as "ONE-CLICK REGISTRATION", right?

Indeed.