If EF crashes when starting the EF-launcher, disconnect your computer from the internet and follow these steps:
1) Start the EF-launcher without any internet connection.
2) Disable auto-updates in the launcher. Close the launcher.
3) Reconnect your computer to the internet.
4) Start the launcher, now everything should work as usual.
Alternatively you can go to your Company of Heroes directory, find "EF_Launcher_Config.ini", open it with Wordpad or any text editor of your choice and replace Auto_Update=True with Auto_Update=False.
The problem is that whenever a patch for EF is released, our server will be very busy and might not respond. The EF-launcher sends a message to the server to get information on possible new versions and - due to a bug - crashes when the server doesn't respond.