KB5003637 (and the new KB5004476) gives error "Failed to load resource: net::ERR_HTTP2_PROTOCOL_ERROR" in web browser using Visual Studio 16.10.1. or 16.10.2.

Question

Hi,

After installing the automatic update KB5003637 3 days ago, building web apps using Visual Studio 16.10.1. or even latest update Visual Studio 16.10.2. produces the error "Failed to load resource: net::ERR_HTTP2_PROTOCOL_ERROR" in web browser (Images, css, etc don't load properly anymore).

It is clear in my case uninstalling the KB5003637 solves the issue. The only problem is when wanting to update Windows 10 it installs that same update over and over again.
The option to exclude/hide the update isn't there anymore, so this is very annoying.

I'm not the only one experiencing this problem as you can find here: https://stackoverflow.com/questions/67911570/failed-to-load-resource-neterr-http2-protocol-error-for-react-app-after-upg/67934980?noredirect=1#comment120151946_67934980.

Also the new update KB5004476 (which replaced the previous update KB5003637) is causing the same error. When installed I get the exact same errors, uninstalling solves it instantly.

Please advise, something is really wrong with these updates.

UPDATE!
Microsoft finally released a fix that works for me, as you can read 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! :)

Thanks in advance!
Kind regards,
Lester De Meyer.

Answer 1

I've been following this thread about the http.sys BSOD since recent updates --> https://answers.microsoft.com/en-us/windows/forum/windows_10-performance/blue-screen-httpsys-error/9c4f6ce7-8141-41ab-bd86-e4cf3afef0de?page=3

Appears related to VS2019 and IIS Express. Some users have had luck by replacing http.sys with an earlier version. I would rather just MS address the issue and put a fix out via windows update.

Answer 2

I had the same problem. Wasted 3 hours of development time thanks to Microsoft's stubborn policy of sending automatic updates when they are not wanted, not needed, and are themselves potentially more destructive than any virus or malware! I uninstalled the update KB5003637 and the problem went away. Many thanks to the person who reported this and who found a solution. Microsoft: please, please do better in future.

Answer 3

For me the workaround of disabling HTTP/2 for IIS seems to work:

1. Regedit
2. Go to path: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\HTTP\Parameters
3. Create 2 new DWORD (32-bit) values:

EnableHttp2Tls
EnableHttp2Cleartext
both set to 0 (should be default)

4. Reboot

Answer 4

Hello!

Any new updates from Microsoft on this issue?

With working in VS2019 and using Ctrl-F5 reload after I make JavaScript changes, I've crashed 4 times within an hour :/

I've tried the following:

• Update RegEdit with the 2 EnableHttp2Tls/EnableHttp2Cleartext (https://developercommunity.visualstudio.com/t/httpsys-blue-screen-when-debugging-a-we/1457526#T-N1458830)
• Have Telerik Fiddler running in the background which uses Http/1 (this seems to cause issues with my desktop office and teams
• We have to run SSL, so I can't do that suggestion
• I cannot uninstall the updates from Microsoft due to company policies

Any other ideas or has anyone heard when they will push a fix via Windows Updates. This is becoming VERY frustrating to all of the developers on my team (even though it has seemed to impact us in different ways/different times)!

Answer 5

Also, for some additional context, the reason disabling SSL works is because most browsers will switch from HTTP/2 to HTTP/1.1 for the requests. The bug is with HTTP/2 implementation, so it's a workaround.

I also submitted this via the Feedback app on Monday and still haven't heard anything there. Glad to see confirmation that it's been accepted as an issue and there will be a fix at some point.