ReactJS: net::ERR_HTTP2_PROTOCOL_ERROR 200 with .NetCore in HTTPS
I am using Visual Studio 2019 and experienced the same problem. This is what I did to resolve it:
Removed 'Microsoft.AspNetCore.SpaServices.Extentions' Nuget package from the project's Dependencies/Packages, and then installed the latest version (Installed 5.0.6)
Cleaned and rebuilt the solution and it started working again.
let me know if it works for you!
Don't have enough rep to comment, but wanted to drop a note saying had the exact same experience as JTM and think that the Win10 update seems to be the likely suspect. .Net Core project that worked fine last night with no changes has stopped working post-update.
This solution does not work for dotnet core. I've tried updating SpaServices.Extensions to the latest version 3.1.16.
A temporarily solution is to disable SSL under Web Server Settings.