This error was driving me nuts too. Windows 10 was updated 2 days ago and I also updated Visual Studio to version 16.10.1. After that, I got the errors, images, CSS not loading correctly.
As SpeedOfSpin mentioned in a comment in a previous post, uninstalling KB5003637 worked instantly for me, no more errors! Everything loads perfectly now.
It wasn't necessary to go back to an earlier version of Visual Studio, it seems it was Windows OS related.
@SpeedOfSpin: Thnx a lot! :)
UPDATE ON ISSUE 1
Today there was a new update KB5004476, I don't see the previous KB5003637 anymore here. KB5004476 is causing the same errors. When installed I get the exact same error "Failed to load resource: net::ERR_HTTP2_PROTOCOL_ERROR", uninstalling solves it instantly again.
I have asked the Microsoft forum what is going on here:
https://answers.microsoft.com/en-us/windows/forum/windows_10-networking/kb5003637-and-the-new-kb5004476-gives-error-failed/db2f2f73-7f5c-477a-b212-5f13c998a09a
UPDATE ON ISSUE 2
As they couldn't provide a solution in the first MS forum (previous link), the same question has been asked here:
https://docs.microsoft.com/en-us/answers/questions/440339/kb5003637-and-the-new-kb5004476-gives-error-34fail.html
Updating Visual Studio to version 16.10.2. doesn't solve the issue either.
UPDATE ON ISSUE 3
After some more testing, it seems it affects the browser Chrome only (As I only use Chrome, as most people do). In Firefox, Edge, and IE it seems I'm not having this issue. It was confusing as I tried so many things and the only solution I still have is uninstalling the KB5003637 or the new version KB5004476. So I guess something is wrong with Chrome after all. For now, I will keep the updates uninstalled, I don't feel like changing my preferred browser.
UPDATE ON ISSUE 4
It is indeed not a Chrome-only issue, sorry guys. Saw the same error in Edge this morning too. It took a long while to recreate the problem, while in Chrome I have it every single time. :(
UPDATE ON ISSUE 5
As asked in the first post here by ChrisP, go to the VS Developer Community if you experience this issue too, and please upvote this problem.
I asked the question there also, but still no solid solution at this point.
https://developercommunity.visualstudio.com/t/Failed-to-load-resource:-net::ERR_HTTP2_/1446262
UPDATE ON ISSUE 6
Two days ago after 1 single refresh (F5), when testing my web application, aside from the HTTP/2 errors, I also had the same blue screen like people are starting to mention. It showed the error "System Thread Exception not Handled" in file "HTTP.sys" and restarted, amazing!
Also, 2 new updates were installed KB5003690 and KB5003537, but nothing changed, I still have the annoying errors. Previous updates KB5003637 and KB5004476, where it started to go wrong, are gone here.
Uninstalling these updates as a workaround isn't the best solution for me, as they get reinstalled when wanting to update Windows 10 (No option anymore to exclude/hide the updates).
For me the easiest/quickest workaround at this point, to test locally with no “Failed to load resource: net::ERR_HTTP2_PROTOCOL_ERROR” errors, no "System Thread Exception not Handled" BSoD! error and most important no stress anymore :), is disabling SSL in the debug settings of your project in Visual Studio. (Right-click Project, Properties, Debug, Web Server Settings below).
Hope this gets fixed quickly!
UPDATE ON ISSUE 7 (SOLVED!)
Microsoft finally released a fix that works for me, more information here (last post):
https://developercommunity.visualstudio.com/t/Failed-to-load-resource:-net::ERR_HTTP2_/1446262?viewtype=all
Installing the most recent update KB5004237 solves the problem in my case. No more "Failed to load resource: net::ERR_HTTP2_PROTOCOL_ERROR" errors, no more “System Thread Exception not Handled” error so far too!
Yay! :)
Kind regards,
Lester.
