[Bug - Partner Center] Uploading a new extension package (.zip) in Partner Center fails

[ieatstickers]

Describe the bug

Uploading a new extension package (.zip) in Partner Center fails. The UI shows a generic "Something went wrong. Please check your network settings" banner. The browser console shows an HTTP 400 "The specified block list is invalid." response on the PUT ...blob.core.windows.net/...&comp=blocklist request, preceded by several failed Put Block requests to the same blob endpoint.

The connection is a stable, verified 1.1 Gbps. A previous version of the same extension uploaded successfully.

To Reproduce

1. Go to Partner Center > Microsoft Edge program > the extension > Packages
2. Click Update / upload and select the .zip package (~34 MB, 657 files, Manifest V3)
3. Wait for the upload progress to complete
4. See the error: "Something went wrong. Please check your network settings"
5. Open browser DevTools > Network/Console and observe a 400 (The specified block list is invalid.) response on the PUT ...blob.core.windows.net/...&comp=blocklist request, preceded by several failed Put Block requests to the same blob endpoint

Expected behavior

The package upload completes and the new version is accepted for review/certification, as with previous uploads of this extension.

Screenshots

Desktop (please complete the following information):

• OS: macOS 15 (Sequoia)
• Browser: Microsoft Edge (also reproduced in other browsers)
• Version: 148.0.3967.96

Additional context

N/A

[Rahul-Bauri]

Hi @ieatstickers please provide us with your extension package as well as the HAR file to help the engineering team investigate the issue further and help with a resolution,

A HAR file is a browser network trace that captures all requests and responses during an issue reproduction, helping us identify failing APIs or performance bottlenecks.

Steps to get HAR file (Chrome / Edge)

1: Open Developer Tools
Open the page where issue occurs

Press:
F12 OR
Ctrl + Shift + I

2: Go to Network tab
Click Network

3: Enable recording
Ensure red recording button is ON

Enable:
Preserve log
(Optional) Disable cache

4: Reproduce the issue
Refresh the page
Perform exact steps causing the issue

5: Export HAR file
Right-click anywhere in the request list
Click: “Save all as HAR with content”

6: Share the file
Send the .har file

[ieatstickers]

Hi @Rahul-Bauri

Please see below for the extension build I'm trying to submit.

The first time I tried to upload and record the HAR file, it timed out rather than errored. Then the second time it errored as described above.

I've included the HAR files for both the timeout and error.

Extension package: https://drive.google.com/file/d/1kXWYQHA4CNQhVb5NH8t4l2Hee9F9dP6d
Timeout: https://drive.google.com/file/d/1HvE5VKnFkJE9mdOHOUCK0nYIBQOzKiGO
Error: https://drive.google.com/file/d/1LhYiX58OovTZ6MQvKu8jB3-rURaHaOji

Please let me know if there's anything else I can do to help debug.

[Rahul-Bauri]

I have shared these details with the engineering team to investigate, will update you once I have something to update on the issue.

[ieatstickers]

Hi @Rahul-Bauri

Are you able to provide a progress update on this one please? We're currently blocked from being able to deploy any updates to our extension including bug fixes that we're keen to get live as soon as possible.

Thanks