Recently, I just created a Modded pixelmon + backpack minecraft 1.10.2 server. I followed a tutorial. When i open the command prompt for the forge jar, it said it failed to bind to port. I already port forwarded... Then the command prompt/console crashes right away. However, when i gave my friends my ip that i found on whatismyip, the server is always up. I have no access to it tho. And yes, i left the server ip blank under properties.
There's a really simple solution for it. Just get in the server and execute "/stop" then try starting server again the port thing means that a server is already up with that port so it must be opened but you can't see console for any reason.