<SOLVED>Firefox 99.0 cannot find a server without a VPN connection

[Kuulessää]

Linux Mint 20.3 and Firefox 99.0. The latest update package caused the phenomenon that Firefox can no longer connect to any server except via a VPN connection. I wonder what's going on here as the Tor browser on the same machine works also without the VPN ?

[LittleScriptMan]

I wonder what's going on here as the Tor browser on the same machine works also without the VPN ?

So, the problem comes from Firefox network settings.
Firefox -> Edit / Settings / General. At the end, you'll find Network Settings.
Check Proxy settings.

[Kuulessää]

So, the problem comes from Firefox network settings.
Firefox -> Edit / Settings / General. At the end, you'll find Network Settings.
Check Proxy settings.

Tried chancing no proxy to automatic/system but no help about that.

[LittleScriptMan]

It may not be that simple. The link to Mozilla support about your issue may help :
https://support.mozilla.org/en-US/kb/co ... gs-firefox

PS : What works for me with or without VPN is "Use system proxy settings", but I wouldn't claim this is a universal patch.

[Kuulessää]

It may not be that simple. The link to Mozilla support about your issue may help :
https://support.mozilla.org/en-US/kb/co ... gs-firefox

PS : What works for me with or without VPN is "Use system proxy settings", but I wouldn't claim this is a universal patch.

Tried No proxy, Auto-detect proxy settings for this network and Use system proxy settings but no help about those variations. Also tried to change on https://support.mozilla.org/fi/kb/firef ... owsers-can suggested IPv6 and DNS Prefetching settings but no help.

[Kuulessää]

Now I noticed that Chromium won't connect without a VPN on either. Only TorBrowser works. I also tried booting with an older kernel, but no effect. The machine is also running WIN10 and on that side Edge works normally.

I'm using HP-Z400-Workstation Kernel: 5.4.0-107-generic x86_64 bits: 64
Desktop: MATE 1.26.0 Distro: Linux Mint 20.3 Una and Network Device-2: Ralink RT5370 Wireless Adapter type: USB driver: rt2800usb

if that tells something.

[LittleScriptMan]

Now I noticed that Chromium won't connect without a VPN on either. Only TorBrowser works. I also tried booting with an older kernel, but no effect. The machine is also running WIN10 and on that side Edge works normally.

I'm using HP-Z400-Workstation Kernel: 5.4.0-107-generic x86_64 bits: 64
Desktop: MATE 1.26.0 Distro: Linux Mint 20.3 Una and Network Device-2: Ralink RT5370 Wireless Adapter type: USB driver: rt2800usb

if that tells something.

Seems your problem is neither related to hardware (works under conditions) nor to Firefox (Chromium doesn't work either).
I see 2 last directions to explore (there may be more but not immediately coming to my mind) :
- check VPN's settings : does it connect at startup ? does it block connections when deactivated ?
- try to create a new Firefox profile with no add-ons and see if the original links (pointing to various pages in the Mozilla area) work without VPN.

PS : a third one
What VPN are you using ? It may be worth a try to consult the FAQ or contact the support service of your VPN provider. Maybe they know something about your issue.

[Kuulessää]

Tried creating a new profile but no help about that. Got some error messages what i do not understand...

"seppo@seppo-HP-Z400-Workstation:~$ firefox -p
[GFX1-]: Couldn't sanitize RENDERER device: NVS 310

###!!! [Child][PContentChild] Error: RunMessage(msgname=PContent::Reply_DiscardBrowsingContext) Channel closing: too late to send/recv, messages will be lost


###!!! [Child][PContentChild] Error: RunMessage(msgname=PContent::Reply_DiscardBrowsingContext) Channel closing: too late to send/recv, messages will be lost


###!!! [Parent][PImageBridgeParent] Error: RunMessage(msgname=PImageBridge::Msg_WillClose) Channel closing: too late to send/recv, messages will be lost

seppo@seppo-HP-Z400-Workstation:~$"

[Kuulessää]

I Timeshifted the system back to 4.4.2022 when Firefox was still version 98.0.2 (kernel is 5.4.0-107-generic) and now the pages load even without the VPN app so there seems to be some bug in version 99.0 ?????????

Now it seems that the problem is with some other component. I updated the system so that Firefox remained at 98.0.2 and the other suggested updates were made and the problem recurred.

I wonder which of those could cause it?

[Kuulessää]

I think it's clear now, it's not Firefox because Chromium and Tor also behave the same way. These threads should give some answers, my problem is exactly the same.

viewtopic.php?f=47&t=365856&p=2124959&h ... N#p2124959

viewtopic.php?f=52&t=359915

[Kuulessää]

It's clear. ProtonVPN's Kill Switch blocks network connections without a VPN if you turn off the machine with the VPN on.

[LittleScriptMan]

Reading the links you provided and especially Xenopeek's answer about issue possibly coming from ProtonVPN and if you're still in testing mode/mood, I would :
- restore your working config with Timeshift
- upgrade the system except the protonvpn-gui 1.8.0-2 (untick it)
- if it works, upgrade FF to 99.0 keeping previous version of ProtonVPN
- if it still works, the issue would be ProtonVPN (which I suspect too) and not Firefox - I use another VPN provider (Mullvad) and everything works fine with FF before and after 99 upgrade.

[Kuulessää]

Yes, it is now confirmed that the problem was related to the Proton VPN killswitch feature. I updated all offered updates (including protonvpn-gui 1.8.0-2) and now everything seems to work normally again. Thanks for the tips I received to solve the problem.