I just installed a new SSL certificate on my server and updated the aMember CP to reflect the new secure root URL. However, the formatting of my member area disappears when I change the secure root to https. Am I doing something wrong? Thanks.
Of course. Try to access "Secure Root URL" you are entering. Do you see the same content as of non-secure "Root URL" ? It should be the same page.
Then of course it won't work. There must be the same page as under http:// - ask your webhosting provider how to get https:// referring to the same content as http:// or contact us via helpdesk for other solutions.