Proton VPN Firefox Extension Pulled From Mozilla Store Pending Mandatory Review

Proton VPN confirmed its Firefox browser extension is temporarily unavailable after Mozilla removed it from the Add-ons store pending a mandatory review.

Users first flagged the problem on the r/ProtonVPN subreddit, reporting that the extension froze on a loading screen and blocked access to features including split tunneling — a tool That Lets users route only selected traffic through the VPN.

Even so, the underlying VPN connection itself remained active for affected users.

Shortly after, the extension’s Mozilla Add-ons store listing went offline entirely, returning a “Page not found” error. Existing installations continued working for some users, but fresh installs failed.

Proton addressed the outage on X, saying core VPN functionality remains available through its desktop app. The extension also continues to work normally on Chromium-based browsers such as Google Chrome and Microsoft Edge.

Workarounds Available, but Limited

Power users can manually build and sideload the extension as an .xpi file — a Firefox-compatible package format — directly from Proton’s GitHub repository. That process requires technical familiarity with browser extension installation outside official stores.

For most users, Proton pointed to the desktop client as the simplest alternative.

No Fix Timeline Given

Proton has not provided a timeline for when the extension will return to the Mozilla Add-ons store. Mozilla’s extension review process can take considerable time, leaving users without a clear resolution window.

Proton VPN is a privacy-focused virtual private network service operated by Proton AG, the Swiss company behind the encrypted email service Proton Mail. The Firefox browser extension lets users control VPN connections directly from the browser without opening a separate desktop application.