Bad Request - Header Field Too Long - TEAMS ADMIN PANEL

Question

Hello everybody.

I clear the cache, i tried with 3 browsers (Firefox , chrome, edge) and i still receive the same error while trying to go on Teams Admin Panel

HTTP Error 400. A request header field is too long.

What should i do?

Answer 1

I have tried clearing these from both Edge and Chrome (I use Both) as well as trying incognito,/inprivate and the issue remains.

??

Answer 2

Hi,
had the same problem and found two sources which guided me to the solution:

Bad Request - Header Field Too Long - Error 400 - Teams Admin Center - Microsoft Community

Bad Request when trying to access to Microsoft Teams Admin Center : r/msp

To fix it, simply remove all roles except for the Global Administrator role from your admin account. This must be done using a second global administrator, as you cannot remove roles or edit settings on a global admin account while logged in as the account itself. If you only have one, just make a second one temporarily so you can complete your changes, and then delete the second account when you complete the work.

This was the final solution and after updating the roles, I finally could login again 5-10min later
Hope this helps :)

Greetings
Thomas

Answer 3

Hi Salanta,

I am happy to hear that uninstalling Firefox, clearing metadata, and doing a fresh install fixed the issue.

Thanks for your feedback.

Best Regards,

Seun

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Answer 4

I have uninstall firefox, clear metadata after uninstall, then new fresh install and it worked!

Answer 5

Hello Salanta,

Thank you for reaching out to the Microsoft Community. My name is Seun and I'm happy to help.

I understand your concerns on the error you are gettting while trying to access Microsoft Teams Admin Centre.

The error "HTTP Error 400. A request header field is too long" indicates an issue with cookies or browser cache exceeding the limit. You've tried clearing the cache, which is a good first step, but there are a couple more things to try:

A) Clear Cookies: While you cleared cache, focus on cookies this time. Cookies can build up and become very large, causing this error. Here's how to clear cookies in different browsers:

Chrome: Open Chrome, go to Settings > Privacy and security > Clear browsing data. Select "Cookies and other site data" and the time range (choose "All time" for best results). Click "Clear data."

Firefox: Open Firefox, go to Settings > Privacy & Security. Under "Cookies and Site Data," click "Clear Data..." Select "Cookies" and "Cached Web Content" and click "Clear."

Edge: Open Edge, go to Settings > Privacy, search, and services. Under "Clear browsing data," choose "Choose what to clear." Select "Cookies and saved website data" and "Cached data and files" and click "Clear now."

B) Try Incognito/Private Window: Open a new incognito window in Chrome, private window in Firefox, or InPrivate window in Edge. Try accessing the Teams Admin Panel there. If it works, it suggests an issue with cookies or extensions in your regular browsing mode.

C) Disable Browser Extensions (Temporarily): Extensions can sometimes interfere with website functionality. Try temporarily disabling all extensions and see if you can access the Teams Admin Panel. If it works, re-enable extensions one by one to identify the culprit.

Lastly you might want to check : https://portal.office.com/servicestatus to be sure there is no service issue in your location.

I hope this informaiton helps, Let me know if you need more help.

Regards, Seun