From time to time, after the login screen in LeadConduit Classic, you might get a blank page instead of the Dashboard, especially using either Safari or Chrome. This is the result of one or more cookies from the LeadConduit platform.
To resolve this, you only need to clear your *.leadconduit.com cookies from the affected browser(s) (especially the leadconduit.com cookie that begins with "ls".) then you should be back in business.
In a pinch, you can also open a tab in Private/Incognito mode and log in if you just need to make a quick change and don't have time for digging around to figure out how to clear out domain specific cookies at the moment.