When accessing K2 web applications a HTTP Error 400 appears: "Bad Request - Request Too Long HTTP Error 400. The size of the request headers is too long"
kbt150058
PRODUCTIssue
Accessing K2 web applications like Designer, K2 Management, Workspace, Tasks etc in some cases presents a "HTTP Error 400. The size of the request headers is too long (Bad Request)" error.
Symptoms
You are unable to access K2 sites.
Resolution
This is most probably caused by having too many cookies in the header during a request to K2 Trust. It's common when using the same browser session to access many sites that each start adding to the cookies in the browser session.
Clearing the browser cache will fix the issue.