d.abaker

I had the same problem and i fixed it. The reason it happened was because my router had assigned my server computer a new IP address. the new address was 192.168.0.102 and my old address was 192.168.0.104 i had to open the server.properties file in the minecraft server directory and change the address line (server-ip=192.168.0.104) to the new 192.168.0.102 address. You can view your current ip address by going to start: run type CMD then type the command IPCONFIG you will see IPv4 address that is your current IP address. You can cure this problem through your router by assigning a static address to your server computer.