[Server was working yesterday but today it isn't.]

You can check if the port is forwarded correctly with a port probe here; https://www.grc.com/x/ne.dll?bh0bkyd2

 

If she's getting "Bad Login" though and your server properties are set to online mode then she won't be able to join - Bad login means she's not authenticated properly on the minecraft.net server and without that your server will decline connections.  You can either tell her to close all the way out of the launcher and re-run (that should fix it, sometimes takes a couple of goes if minecraft is under heavy load) or you can turn off online mode (not always a good idea, it means anyone can connect with any name and therefore take over other players, not to mention the impossibility of banning someone who can just change names and reconnect).

 

Maybe you didn't see my comment, but - my ports are forwarded, I already checked through all that.

 

It worked yesterday and I did not change the aforementioned setting. She has a Minecraft account, too. Thanks anyway.

[Server was working yesterday but today it isn't.]

"My ports are forwarded". That means I already checked through all that.

Thanks for replying though

[People cant connect to my server]

@ mindlessdream - why did you recommend them to download uTorrent?

 

Because my vanilla server won't let people connect if utorrent isn't running with the listening port to 25565, so I assumed it's the same with Attack of the B-Team. Apologies, guess that's not how it works here.

[Server was working yesterday but today it isn't.]

I can join fine, but my friend suddenly can't join. This results in the server log:

 

[SEVERE] Reached end of stream for /{IP address}
2014-03-29 14:35:52 [SEVERE] Reached end of stream for /{IP address}
2014-03-29 14:35:52 [INFO] {player} [/{IP address}] lost connection
2014-03-29 14:35:54 [SEVERE] Reached end of stream for /{IP address}
2014-03-29 14:36:01 [SEVERE] Reached end of stream for /{IP address)

My friend also says she gets the message 'bad login'.

 

My IP has not changed at all, my ports are fowarded, UTorrent is running, the server is running (Tried with Bteam.jar & Launch.bat)

Mods are default, and I have not installed anything else. 

 

I may try deleting all the files and re-creating the server.

 

[People cant connect to my server]

Did you give them your public IP address? 

 

Download uTorrent and change the connection port to 25565.