Forum Discussion

PanosGR191's avatar
PanosGR191
MCT
Jul 28, 2026

Open in VS Code for the web fails ... tunnel 400 error ?

Hello everyone,

The last week I have problem connecting to VS Code for the Web,

my cloudshell works correctly, my account is ok, everything works BUT when tryont to open through browser - azure portal the VS Code for the Web, I got errors similar to ....

***************************

https://ccon-prod-northeurope-aci-01.servicebus.windows.net/.../tunnel

Result:

400 Bad Request

Response:

{"error":{"message":"Error creating dev tunnel","details":""}}

 

Tested from:

- Multiple browsers

- InPrivate

- Different PC

- Azure VM

***************************

 

I even renamed ~/code , ~/.vscode-server-insiders

and restart cloudshell and VSCode web, same errors (and folders were not recreated)

 

Any help would be greatly appreciated !!

BR,

Panos

 

azure
developer tools

4 Replies

    • PanosGR191's avatar
      PanosGR191
      MCT
      Jul 29, 2026

      Hi,
      I don't think the local environment is the problem because I have reproduce the problem testing on 
      different browsers, InPrivate-Incognito windows, clearing cache , connecting from another pc - server - even from azure vm (!!) 

      And again just to be clear, I am talking about launching-opening from the azure portal the "VS Code for the Web" button , and NOT the editor button ! (the editor button works .... all other parts inside my cloudshell session works !!) .

      I haven't collect all logs, will do it the next hours that I will have some available time, but unfortunately I don't know if I can open a support ticket because the Subscription is a VisualStudio offering , and doesn't have tech.support plan available ! :( 

      Anyway thanks for your time , I hope I will find a way to send those logs to MS support (even without proper "support plan", ) and solve the problem, 

      Many thanks

      Panos

  • Jamony's avatar
    Jamony
    MCT
    Jul 28, 2026

    Your Cloud Shell session works, but “Open in VS Code for the Web” fails while creating the Service Bus tunnel. Because the 400 response occurs in several browsers, another PC, and an Azure VM, local cache or VS Code folders are unlikely causes. Microsoft documents this feature as transferring the Cloud Shell session to browser-based VS Code, so unchanged folders fit a failure before the remote editor starts. First, open Cloud Shell Settings and select Reset user settings. This ends the session and unmounts linked storage but does not delete the Azure file share. Reattach the share and retry. Confirm that HTTPS and WebSocket traffic to the Service Bus endpoint is allowed. If it still fails, select View Logs and open an Azure support request with the UTC time, region, tenant and subscription IDs, and correlation or activity IDs. The 400 response does not identify a user-side fix.

    • PanosGR191's avatar
      PanosGR191
      MCT
      Jul 28, 2026

      Thanks Jamony, 
      I've already tried all actions above, even reset the cloudshell , but the problem remains.
      I even tried to create a new tunnel going directly to https://vscode.dev/azure , reauthenticate, but have same-similar errors .. 

      Strange thing is that everything else is working, even trying to access directly 

      curl -I https://ccon-prod-northeurope-aci-01.servicebus.windows.net I have connectivity 

      I cannot open a ticket because the problem exists on a VisualStudio promote subscription, and I dont have support for tech issues on that ! 
      (But unfortunately I am using this tenant to teach stuff to azure clients .. !! ) 

      Anyway, I hope I will try it later on and maybe get a result !
      Thanks for your help

      Regards,
      Panos