net::ERR_HTTP2_PROTOCOL_ERROR for a single user when using an Angular + ASP.NET Core application

Note: I am posting this here because I think this is more related to some configuration issue rather than a programming problem

I have deployed an Angular (SPA) + ASP.NET Core application in a k8s cluster and it works fine for all the users so far (devs, testers, internal clients). However, for a single colleague, the SPA is unable to fetch API resources due to the following errors:

Failed to load resource: net::ERR_HTTP2_PROTOCOL_ERROR

Failed to load resource: net::ERR_CONNECTION_CLOSED

Note: the same application works fine for that user when deployed in IIS.

My colleague is using Windows 10.

Things I have tried:

• change browsers: the same happens in Firefox, Chrome and Edge Chromium
• tried Incognito / InPrivate
• tried to disable HTTP2 in the ASP.NET Core 2. Chrome Developer tools still reports h2 (HTTP2) connections and this might be caused by the fact that an nginx is handling connections between the SPA and the API running in the pod
• allowed remote access for the user on two different servers and try to access the site from there. This rules out possible Windows configuration issues on his own machine. The site works normally for all others when trying from these remote machines.

I am left with no clues about what might be the cause. My only guess would be that it is somehow linked to a profile misconfiguration which is replicated when the user logs in using the same profile in another machine.

Any ideas about what to try?

Just discussed it with that colleague and the problem no longer occurs. There is a chance that the VPN (Cisco AnyConnect) interfered with this, as the person works both in the office (no VPN) and from home (VPN required). The problem seems to be disappeared after trying Incognito and VPN active, but we try to reproduce it again to fully understand the cause.

posted 10 months ago

CC BY-SA 4.0

10mo ago

Alexei‭

214 reputation 7 3 31 40