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Your browser sent a request that this server could not understand. Size of a request header field exceeds server limit.

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Your browser sent a request that this server could not understand. Size of a request header field exceeds server limit.

Your browser sent a request that this server could not understand. Size of a request header field exceeds server limit.

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A common reason for that message is a problem with the cookies Firefox has accumulated for the site.

You can remove the site's cookies while viewing any page on the site. Call up the Page Info dialog using either:

  • right-click (on Mac Ctrl+click) a blank area of the page and choose View Page Info > Security > "View Cookies"
  • (menu bar) Tools > Page Info > Security > "View Cookies"
  • click the padlock or "i" icon in the address bar, then the ">" button, then More Information, and finally the "View Cookies" button

In the dialog that opens, the site's domain (e.g., google.com, mozilla.org) should be pre-filled in the search box at the top of the dialog. If you can't open Page Info on the actual site, enter its domain name at the top to filter the list.

Then you can remove that site's cookies individually without losing all your cookies for other sites.

Close Page info and try reloading the page. Does that help?