So I was having issues with my TT for pretty much anything Zweihander related, on account of not being able to gate from Witberg to Zweihander. I luckily got to sit down and have a chat with Blacklung(IS GOD BTW), and we tried numerous things that could be the cause. Causes Determined
Make sure all 4 check-boxes next to the server list are checked.
Files may be corrupt( Reinstall via https://forum.enb-emulator.com/index.php?/topic/9469-how-to-get-into-the-game/ )
ISP Issues - Can be solved via router settings or contacting your ISP
Validate a clean Uninstall/Install of Net7/EnB Client
Disable Anit-Virus or add Exceptions to the folder(not just the file)
If you have any questions also the teamspeak (net-7.org) is a great place to find what you need.