Forum Discussion

Olof's avatar
Olof
Icon for Nimbostratus rankNimbostratus
Sep 18, 2025

APM webtop – problem with websockets for Serverside Blazor app

Dear community,    We have a web application built with Blazor server side rendering that utilizes SignalR (websockets) and runs on a Windows server with IIS (i.e. not web assembly).   Virtual se...
APM
application delivery
signalr
virtual server
websocket
webtop
Olof's avatar
Olof
Icon for Nimbostratus rankNimbostratus
Sep 29, 2025

Hi Jeffrey,

Thank you for the response!

 

We have tried the WebSocket profile now (with and without preserve), but unfortunately the handshake still times out.

I adjusted the handshake timeout in the Blazor app, but it only delays the error message. 

 

A colleague found an article that hinted it might be an issue with javascript versions: https://my.f5.com/manage/s/article/K15142093 

 

We have written very few javascripts for the app and tried deactivating them completely without effect. But Blazor generates a “blazor.web.js” script that is served to the client. 

I haven’t found any clear information about the javascript version in that script, but an issue on github had a complaint about “high version syntax”. That issue regarded .NET9 and we use .NET8, but the issue was resolved with a comment that Microsoft only supports the latest web browsers: https://github.com/dotnet/aspnetcore/issues/59090

Could javascript version be the issue?