Size of a request header field exceeds server limit. This is normally caused by having a very large Cookie, so a request header field exceeded the limit set for Web Server. For client side: Clear the the cache of your web browser should be fine.Click to see full answer. Also asked, what does size of a request header field exceeds server limit mean?Size of a request header field exceeds server limit. That means that your browser is trying to send too much at once. Probably, it’s size of the cookies. The easy way to fix it – delete cookies. Of course, you lose all info in the cookies, but at least you can access site again.Furthermore, how do I fix request header or cookie too large? Under the ‘All Cookies and Site Data’ find your domain and remove its cookies. After removing the cookies of that particular website, restart your Google Chrome browser and then open the website. You won’t get the Request Header Or Cookie Too large error anymore. Besides, what does this mean HTTP Error 400 the size of the request headers is too long? The HTTP 400 error occurs if the HTTP header is too long. In principle, headers don’t have a size limit, however, the target server may have set a limit. The header consists of several fields, in which requests and answers are defined. If both callers have matched the parameters, the requested data will be exchanged.What does it mean your browser sent an invalid request?The “400 Bad Request error” is an HTTP status code that means the request you sent to the website server (i.e. a request to load a web page) was somehow malformed. Therefore the server was unable to understand or process the request or it could be also due to oversized cookie.