Hello, thanks for your question and sorry for the troubles.
If you are having issues logging into cPanel from a bookmark, this could possibly be caused by cPanel security tokens. Although that's been in place for some time now.
Are you attempting to login to cPanel directly by accessing either of these URLs and still having issues?
http://example.com/cpanelhttp://secure104.inmotionhosting.com/cpanel
If you are behind a firewall blocking the cPanel port of 2083, then you'd want to use the cPanel proxy instead:
http://cpanel.example.comhttp://cpanel.secure104.inmotionhosting.com
Or are you attempting to login from our AMP interface by clicking on the cPanel link?
If you can please provide a bit more info about how your web-browser is trying to access cPanel, we'd be glad to offer further suggestions about what might be going wrong.
- Jacob