To bad-badger///
"1. select: "Do not allow any sites to handling protocols" in Opera Preferences (privacy and security)..."

Нowever, this creates many other problems and inconveniences! Don't you know?

Every time you start Opera spontaneously becomes the mail client by default.
How to stop it ???????

after updating 40.0.2267.0, every time when I try to enable VPN, browser emergency shuts down and restarts