Try uninstalling, deleting your Evidyon folder, and reinstalling. If that does not work, then your server IP may be incorrect. To fix it:
1)Install Evidyon
2)Download updates via launcher
3)Open your c:/Program Files/Evidyon/ folder
4)Open "config.ini" using Notepad
It should look like this:
config.ini wrote:[Audio]
Enable=1
[Graphics]
ColorDepth=32
ForceSoftwareRendering=1
Fullscreen=1
MaximumFramesPerSecond=45
ResolutionX=1680
ResolutionY=1050
[Media]
MediaFile=evidyon.evcli
[Network]
Server1=66.96.229.53
Check that bolded server1 IP. If it isn't the same, correct it. That's the problem I had when I couldn't log in =)
Hope it helps,
Erich