Sending more than 8K of HTTP headers breaks CloudFlare. You can't access the backend of the site. The frontend is fine.
normally it's a plugin adding stuff, but WP sends some stuff too. I can't read the encoded stuff, but has anyone seen this issue?
"name": "cookie", "value": "wordpress_sec_...; __cfduid=...; PHPSESSID=...; wordpress_test_cookie=WP+Cookie+check; wordpress_logged_in_...; wp-settings-1=libraryContent%3Dbrowse%26editor%3Dtinymce%26urlbutton%3Dnone%26ed_size%3D704%26hidetb%3D1%26align%3Dnone%26imgsize%3Dfull%26wplink%3D1%26unfold%3D0%26mfold%3Df%26advImgDetails%3Dshow%26posts_list_mode%3Dlist%26editor_expand%3Doff%26edit_element_vcUIPanelWidth%3D1189%26edit_element_vcUIPanelLeft%3D259px%26edit_element_vcUIPanelTop%3D104px%26panel_vcUIPanelWidth%3D650%26panel_vcUIPanelLeft%3D951px%26panel_vcUIPanelTop%3D74px; wp-settings-time-1=...; cf_use_ob=443; cf_ob_info=..."Looks like it's mainly wp-settings-1