[New website] App links broken

At https://help.musescore.com/, the links to the apps in the footer are currently broken:
- iPhone/iPad goes to https://help.musescore.com/ios
- Android goes to https://help.musescore.com/android
- Kindle Fire goes to https://help.musescore.com/kindle
- Windows Phone goes to https://help.musescore.com/apps/windows-phone – this gives an error: "Invalid parameter: id must be an integer"

Curiously, https://musescore.org/ doesn't have a link for Windows Phone at all.