Post actualizado el día octubre 25, 2026 by DeiviSanzPlay
Proton VPN has changed more in the last two years than in its entire previous decade. The arrival of WireGuard as the default protocol, the redesigned Windows and macOS app, the rollout of 10 Gbps servers, and the strengthening of the anti-censorship system have brought clear improvements, but also a family of new bugs that don’t appear in older guides. If your connection gets stuck on «Connecting…» or the kill switch leaves you without internet even after disconnecting, what follows is designed for that specific scenario.
What has changed in Proton VPN and why different failures appear
Proton’s official documentation confirms several design decisions that explain most current issues:
- WireGuard as the main protocol on most platforms, with Stealth and Smart Protocol as automatic alternatives.
- Permanent kill switch on Windows that is enabled by default and blocks all IPv4/IPv6 traffic when the VPN drops.
- Account migration to Proton’s unified ecosystem (mail, drive, pass), which sometimes causes session conflicts.
- Port and protocol blocking on corporate, university, and some ISP networks that now detect WireGuard tunnels by packet signature.
The result is that many «errors» are no longer app bugs, but incompatibilities with the network you’re connected to or with the previous configuration left over from earlier versions.
The most reported failures on forums and support (and their real origin)
1. It stays on «Connecting» or «Searching for server» indefinitely
This is the most common one. In most cases it’s not the app: it’s the network. Proton VPN uses UDP with WireGuard, and many public networks silently discard it. The solution is not to reinstall, but to manually switch the protocol to Stealth or, if available, to OpenVPN TCP on port 443. In the desktop app, you do this in Settings → Protocol → disable «Smart» and choose a specific one.
2. The kill switch leaves you without internet after disconnecting
A classic failure of the transition between versions: the Windows firewall rule stays active even after you close the app. According to Proton’s own help center, the persistent kill switch should be disabled from the interface before uninstalling. If you can no longer open it, you need to run the official repair tool from the Windows control panel and restart. On macOS, the equivalent is to check the configuration profile in System Settings → Network.
3. Authentication error 400 or «session expired» after updating
The migration to Proton’s unified ecosystem caused older accounts with a password different from their Proton Mail one to be unable to sign in. The solution is to reset the password from account.proton.me, not from the app. If you have 2FA enabled with an app you no longer use, you’ll need the recovery codes.
4. Speed much lower than expected on «Plus» servers
Here there’s a nuance almost nobody mentions: free servers and some Plus servers share an IP with hundreds of users. Proton has been adding 10 Gbps servers and features like Smart Routing, but if your ISP applies QoS to VPN traffic, no server is going to fix that. I’ve seen it in installations with 1 Gbps fiber where a Proton server in the Netherlands gave 80 Mbps and the same server with WireGuard by default rose to 500 Mbps just by changing ports.
Quick diagnosis before touching anything
Before reinstalling or opening a ticket, it’s worth ruling out the obvious, which is what resolves most cases:
- Try from another network (mobile data). If it works, the problem is your local network or your ISP, not Proton.
- Disable IPv6 on the adapter. Proton VPN handles it, but some home routers filter it and break the tunnel.
- Check the service status. Proton publishes incidents on its status page; sometimes the «error» is a server being down.
- Check the system time. A drift of more than 5 minutes breaks TLS authentication and produces errors that look like network issues.
What doesn’t work (and you should accept)
There are real limits. Proton VPN cannot guarantee access to services that aggressively block VPN IP ranges, such as some banks or streaming platforms. There’s also no magic solution if your network blocks all UDP traffic and doesn’t allow Stealth: in that case the VPN simply won’t connect, and forcing it with retries only makes the experience worse. And if the problem is that Windows’ persistent kill switch got corrupted, the most reliable route is a clean uninstall with the official tool, not manual registry edits.
Outlook for 2026
The trend is clear: fewer «app errors» and more network conflicts. Proton is pushing WireGuard and Stealth, and ISPs and corporate networks are responding with more inspection. If you use Proton VPN daily, having the protocol switch at hand and knowing how to disable the kill switch before uninstalling will save you most issues. For the rest, official support remains the only reliable channel: there are no shortcuts that fix a network that blocks the protocol.
