topic Re: 400 Bad Request error in Chrome on devnetsandbox.cisco.com in DevNet Sandbox

400 Bad Request error in Chrome on devnetsandbox.cisco.com

bmcgahan — Mon, 24 Nov 2025 18:44:20 GMT

Does anyone else run into this issue on Chrome, where after logging into https://devnetsandbox.cisco.com
with your CCO login, it returns this Request Header or Cookie Too Large HTTP 400 Bad Request error?

I can fix it every time by right-clicking > Inspect > Application > Clear site data... but I'm not sure it's supposed to work that way 🙂

It seems to be platform independent, Chrome on Windows and MacOS have the problem. Firefox on either does not.

Re: 400 Bad Request error in Chrome on devnetsandbox.cisco.com

Jesus Illescas — Mon, 24 Nov 2025 18:51:40 GMT

This is an unfortunately known issue @bmcgahan. Clearing the cookies is the only solution. Is not a problem on the sandbox side, but rather on SSO across Cisco sites.

Re: 400 Bad Request error in Chrome on devnetsandbox.cisco.com

bmcgahan — Mon, 24 Nov 2025 19:03:32 GMT

I guess a known issue is at least better than an unknown one, right?

Re: 400 Bad Request error in Chrome on devnetsandbox.cisco.com

bigevilbeard — Mon, 24 Nov 2025 21:46:12 GMT

Sup @bmcgahan I always use an incognito browser

Re: 400 Bad Request error in Chrome on devnetsandbox.cisco.com

Jesus Illescas — Tue, 25 Nov 2025 07:12:14 GMT

@bmcgahan indeed, known are always better than unknowns. I'm thinking we need here on the community and in our sites some sort of FAQ for known issues. I will see how to make it happen.