my link is broken too, but i can fix it manually (you should be able to also) : there is an extra "forums/" in the url. if you remove it, you arrive in the user cp. the url when i click is :
https://www.mobileread.com/forums/forums/usercp.php
it should be :
https://www.mobileread.com/forums/usercp.php
since the link is the same for everyone, try to click directly on the second link in my message : that should work.