When does this error pop up for you?
Are you getting this after you sign in with your e-mail address?
Or does it appear as soon as you open the app, or when?
Also, what version of Mac OS are you running?
Are you running any security software, like firewalls or proxies?
It occurs at launch both at app launch and when clicking "Sign In" from the menu bar icon. I am working on a corporate network, however I am not behind any port restrictions or firewall. This is not local to only my machine; other EI users here also experience this problem.
It should also still work if you click Cancel, though you won't be able to sign in and get access to full features (unlimited connections).
Also, do you have a wired or wireless connection?
And can you try running 'traceroute adobe.com' from a Terminal window and provide the results here (or PM them to me if preferred)?
You're correct, it does still seem to work. The same alert is triggered on both wired and wireless. I'll PM you the traceroute results shortly.