Why won’t Proton VPN start on my Linux Mint setup?

It's a good idea to mention your distribution and any hardware details when asking for help with technical issues! I've had experience with Flatpak apps not working smoothly, so I recommend trying a native installation instead. Since you're on Mint, which is based on Ubuntu, follow the Ubuntu installation instructions on Proton's support page. Don't feel overwhelmed by the terminal; it can be quite simple once you get the hang of it! Also, many Flatpak apps can have permission issues, which you can manage with Flatseal. Have you noticed if other Flatpak apps are causing problems too?

If you're looking for an alternative, you can use the default OpenVPN client with ProtonVPN. However, remember that you won't get access to all the advanced features of their GUI client this way. If the commands you tried from the website didn't work, it would help to share the commands you're running and any error messages you encountered.

Did you know that the Vivaldi browser has Proton VPN integrated? It works great with Mint Cinnamon, so you might want to give that a shot if you're looking for something quick to try out.

There have been reports of issues with the Flatpak version of Proton VPN, often related to insufficient permissions. Since you're using a Debian-based distro, I suggest installing a native package instead, which you can find in their official documentation for Ubuntu. This might resolve your problems more effectively.