Troubleshooting

macOS says the app "cannot be verified"

The app is not code-signed yet, so Gatekeeper blocks the first launch. This is expected and you only have to do this once:

1. Try to open the app once (double-click it). macOS shows the warning. Close it.
2. Open System Settings → Privacy & Security.
3. Scroll down: you'll see "Global Maths Club was blocked…". Click Open Anyway.
4. Confirm in the dialog that appears.

The app opens normally from then on.

Windows shows "Windows protected your PC"

SmartScreen warns about installers it hasn't seen often, which includes new, unsigned apps like ours:

1. On the blue SmartScreen dialog, click More info.
2. Click Run anyway.

The installer then runs normally. You only see this once per version.

The Linux AppImage won't start

An AppImage must be marked executable before it can run:

chmod +x global-maths-club_*.AppImage
./global-maths-club_*.AppImage

If you prefer a system install on Debian or Ubuntu, use the .deb package instead: sudo apt install ./global-maths-club_*.deb.

If the AppImage still doesn't start, your distribution may be missing FUSE. On Ubuntu 22.04+ install it with sudo apt install libfuse2.

The browser sign-in doesn't return to the app

When you sign in with Google or GitHub, the app opens your browser, and the browser sends you back via a special globalmathsclub:// link. Two things can get in the way:

• The browser asks for permission to open Global Maths Club. This is normal. Allow it (you can tick "always allow" to skip the question next time).
• Nothing happens after the browser finishes: use the "Return to Global Maths Club" button on the browser page. If the app still doesn't react after about a minute, the sign-in page offers a fallback path: follow the instructions it shows, or close the browser tab and try again from the app.

I can't sign in / my account seems locked

After repeated failed sign-in attempts, the account locks temporarily. This protects it from password guessing. The sign-in screen shows how long to wait. You can:

• wait for the countdown to end and try again carefully, or
• use Forgot password? to reset the password. The reset path stays available even while sign-in is locked.

The verification email never arrived

1. Check the spam / junk folder for a message from globalmaths.club.
2. Make sure the address you typed is the one you're checking.
3. After about a minute, the app lets you resend the email.

If it still doesn't arrive after a few tries, wait fifteen minutes (resend requests are rate-limited), then try once more.