PR_END_OF_FILE_ERROR, PRotonVPN, and Firefox

I’ve been using Proton on Windows for a couple of years now without any problems. But the last month or so I’ve started running into something that is driving me ABSOLUTELY NUTS and I figured it was worth posting here about to see if anyone else is, too. I use Proton’s windows app, and have it set so that Firefox always routes through it, but other programs (like Steam or videogames) don’t.

I keep having pages fail to load with PR_END_OF_FILE_ERROR. It happens seemingly randomly, thought Reddit and Amazon seem to do it more than other websites do. It only happens when connected to Proton- I’ve checked a few times by turning it off and browsing the internet as normal.

Nothing about my home connection has changed recently. This started happening about a month ago, and has been getting progressively worse since it started. Now it happens multiple times every hour, and it’s starting to get really, really annoying. I’ve tried everything I can think to try- switching servers, turning off netshield, different levels of netshield, port forwarding/not port forwarding servers, port forwarding on/off, nothing has seemed to impact it. It seems to me like the problem is something with Proton’s servers, as much as I hate to say that. I haven’t tried other browsers (I don’t think that would be the issue, from a bit of googling) and I’ve disabled all of my extensions a couple of times- it’s not a FF problem.

Has anyone else been running into this? Have you found a solution?

Have you made sure that both the Proton VPN app and the Firefox browser are updated to their latest versions?

Does the issue persist after clearing your browser’s cache and cookies, or when using your browser in private/incognito mode?

Which exact servers are you experiencing the issue with (e.g. CH#10)?

Contact us at https://protonvpn.com/support-form with more details and some answers to the above questions so we can have a better understanding of the issue and assist you further.

u/Background_Milk_69 Did you ever find the reason for this? I can confirm this is a problem. It is intermittent (and infuriating) - it will start happening randomly, lasting a few minutes, and then completely disappear (with no changes in configuration etc). I do not believe it is related to the browser version, cache, incognito mode, or Proton server number, etc. It seems to be more like some obscure problem with data transfer …

Can you open a support case with the team please?