If the Catan Online World Client can not connect to the server and the status is "red", it could be one of the following reasons:

1. For maintenance reasons, the regular server restart occurs around 10 a.m. CET, meaning that for several minutes the server is unreachable. In this case, please try to connect again at a later moment.
2. You are using a proxy to connect to the Internet. However, the Catan Online World client requires a direct connection to the Internet.
3. Your firewall is blocking the connection. Some of the firewalls installed on your computer have to be adjusted so that they allow outbound connections to the COW server game.catan-onlinewelt.de i.e. 213.155.94.150 on TCP port 5000 and 5050 for the program javaw.exe. When first starting the client, the firewall program normally asks if you want to allow connection; maybe you denied connection. Please check your firewall settings regarding this. (Various firewalls may be installed on your computer; however, a router firewall normally doesn’t cause problems.)
4. Your provider or network administrator is blocking access. Some Internet providers (mostly 3G/mobile providers) block “non-standard” ports, basically to prevent P2P file sharing. However, in company networks, schools, and other public buildings such ports are mostly blocked too, in order to prevent gaming at the workplace. While Internet surfing is possible that way, programs such as the Catan Online World unfortunately cannot be used.