I know a similar question is already asked earlier at stack overflow but it didn't worked for me. Kindly read the entire question before answering/commenting.
I have implemented AD B2C in two web application all were working fine till last week. Now all of a sudden we are getting
Bad Request - Request Too Long HTTP Error 400. The size of the request headers is too long.
when the user tries to login into the website. Since my website requires every user to be logged in, it has blocked us completely.
My web app are also not working in incognito/inprivate window. Browser: Chrome, Firefox and Edge
When I open the application in chrome(not incognito) after deleting all the history I can see there are around 160+ cookies from the the web app url.
Yes too much cookies seems to be killing my webapp, but its happening even after deleting all the history of browser and in private browsing too.
Even I have reduced the claims attribute to 3 suspecting that more claims attributes might be increasing the header size.

I have tried this too but in vain.
Bottom Line: Deleting cookies and reducing claims both are not working for us and we are blocked. Thanks in advance.