Wao.. This is a really annoying problem. I was playing on my own server and my whole house went dark due to a storm. I booted up my PC and as usual, launched the server. I'm pretty sure it's online, but i can't connect. At first it shows bad login and I tried solving the problem with the ideas posted in this thread everything didn't work.
http://www.canyouseeme.org/, by typing my port "25565" in the box, it tells me if my port is in service or not. At the moment it's running so it's in service, but i can't login like before.
I've tried "localhost", ip, static ip(which is internal ip i guess which i got it by typing "ipconfig" in cmd), I checked if i port forward correctly and doubled check if anything changed. Both true and false for online-mode. I'm using AVG 2013, and yes, I did allow the port deep in the firewall settings.
Well, the server was running perfectly with me playing on it. I really have no idea how in the world 1 short-circuit caused by a single lightning can cause a problem like this. *blank* I was playing/hosting on Tekkit(Main) btw.
Update: A few hours laterSo I've come to realize that, the reason that I could not reach the server was the "world" file (I think). I created a new server just to test, it worked perfectly fine with all the mods and stuff, but when I replaced the "world" file from my previous server, on the server list it tells me "Can't reach server". Being a small private server with just 2-3 friends of mine playing, well, we decided to start anew. :/ Unless anyone have any idea of fixing this.. T_T