If you are receiving this error message, it may be because you are launching the game via the incorrect file.
The correct file to launch the game from is the "TurbineLauncher.exe" file in your game installation folder. By default, the game installs to "C:\Program Files (x86)\InfiniteCrisis". You can create a shortcut to this file by right-clicking it and selecting "Send to" > "Desktop (Create Shortcut)".
If there is no reported down time, this can also occur if a local proxy host is active and preventing the log in functions.
On the launcher's "Options" menu try 'disable proxy' and let it restart, but if that has no effect open the Windows Control Panel and within there select Network and Internet > Internet Options and under the connections tab click on LAN Settings (button).
Under that section if any of the three options are activated ("automatically detect settings", "use a configuration script" and/or "use a proxy server") deactivate them and click ok then ok on the internet options panel.
Before launching the game though, make sure that those settings persist by going back into LAN Settings and double-checking them. If they have been reactivated launch Internet Explorer using a right-click and 'run as administrator' and get to LAN Settings there via the gear icon and try disabling them again (the permissions change should prevent them being reactivated).
Once it is confirmed the settings are off and staying disabled, try launching the game again to test as well.
Important Note: If a proxy host is running and the settings persistently reactivate themselves in LAN Settings, it may be due to two possible things.
First is web filtering and internet security suites that run as a 'local proxy' to filter/block and monitor web access (examples include Netnanny and similar web filtering apps, or any antivirus that has a 'Run as proxy' option to scan/filter web connections). Whitelisting the url's *.infinitecrisis.com and *.turbine.com (they should support asterisk use in this manner) in these applications list of "allowed sites" or "allowed URL's" should enable the launcher and game to connect and function normally.
Secondly, though adware/malware often also sets itself up as a persistent local proxy host. We would recommend in instances where the proxy option is active that you update and run full system scans with your antivirus and antispyware utilities as well. Often, these are 'adware' based items that are not rated 'high threat' by antivirus as all they do is run as a local proxy host to inject advertisements onto the sites visited in the browser, so if your antivirus reports no detections, run a general malware type scanner for spyware/adware as well.
If you are continuing to receive this error after all the above steps, please follow up with Technical Support by submitting a help request here.