Unable to browse or install any extension

[lousilver]

Type: Bug

In a browser I am able to visit https://marketplace.visualstudio.com/

However, in vscode i am unable to browse or install extensions. I get the same error whether browsing, or installing (Python) from the website: "failed to fetch". I've tried manually downloading "SVG viewer", and that said json was missing from the package (I thought maybe a dependency, but chatgpt insists no).

I've had mixed results with Windows defender. Disabling it would enable browsing and installing extensions in vscode. But turning on defender and adding a firewall rule for vscode would not. So then I disabled Defender Smartscreen, and initially it would work then as well. And then, with no change in settings or installs, extensions stopped working.

VS Code version: Code 1.100.2 (848b80aeb52026648a8ff9f7c45a9b0a80641e2e, 2025-05-14T21:47:40.416Z)
OS version: Windows_NT x64 10.0.26100
Modes:

[lousilver]

Currently, for the time being at least, disabling proxystrictSSL inside vscode has helped.

[Neelima10735584]

Thanks for the update, could you please submit a Fiddler trace recording to look further or share details by using MTR.

To capture MTR:
Download WinMTR.

Enter marketplace.visualstudio.com as the hostname and click Start.

Wait until the Sent column is >= 100.

Copy text to clipboard, share with us.

Regards,
VS Marketplace Team

[lousilver]

I had no trouble accessing via browser, the issue was in vscode only.

|------------------------------------------------------------------------------------------|
|                                      WinMTR statistics                                   |
|                       Host              -   %  | Sent | Recv | Best | Avrg | Wrst | Last |
|------------------------------------------------|------|------|------|------|------|------|
|#####################################    -    0 |  111 |  111 |    1 |    3 |    9 |    5 |
|#####################################    -    0 |  111 |  111 |    9 |   19 |   32 |   23 |
|#####################################    -    0 |  111 |  111 |    9 |   18 |   32 |   23 |
|#####################################    -    0 |  111 |  111 |    8 |   18 |   26 |   22 |
|#####################################    -    0 |  111 |  111 |    9 |   20 |   56 |   22 |
|                   No response from host -  100 |   23 |    0 |    0 |    0 |    0 |    0 |
|         ae20-0.icr02.yto20.ntwk.msn.net -    0 |  111 |  111 |    9 |   22 |   71 |   14 |
|         ae24-0.ier02.yto30.ntwk.msn.net -    0 |  111 |  111 |   10 |   20 |   56 |   23 |
|#####################################    -    0 |  111 |  111 |   10 |   19 |   32 |   23 |
|                   No response from host -  100 |   23 |    0 |    0 |    0 |    0 |    0 |
|                   No response from host -  100 |   23 |    0 |    0 |    0 |    0 |    0 |
|#####################################    -    0 |  111 |  111 |    9 |   19 |   32 |   23 |
|________________________________________________|______|______|______|______|______|______|
   WinMTR v0.92 GPL V2 by Appnor MSP - Fully Managed Hosting & Cloud Provider