Someone else here gave me a pointer when I was running into this on the USPS site.
Clear your cookies for that site. (In Chrome/Edge, go to the site, open up the dev tools, go to the "Application" tab, find cookies, delete them all).
Something probably went a little nuts with the site and ended up creating too much data in one or more cookies.
-A
For the last two weeks we have been unable to pay any bills on the
business Comcast website.
Clicking on any billing link results in:
400 Bad Request
Request Header Or Cookie Too Large
This is going to the URL of:
https://business.comcast.com/oauth/oauth2/authorize?client_id=comcast-business-myaccount-prod&response_type=code&redirect_uri=https%3A%2F%2Fbusiness.comcast.com%2Faccount%2Fbilling
Even trying to log out from the customer portal results in:
Sorry
Something went wrong. Please check back later.
This is going to this URL:
https://business.comcast.com/account/logout
Hoping someone on here can get this to the right people to fix. I'm
sure Comcast would love to get payments from their commercial customer base.