Why can't anyone log in to my server?

[Hotelmariofan]

I recently installed RemoteToolkit to my server and now no one but me can login to the server. The server runs on my network. Why would this be? I mean I haven't changed anything other than turned on restart and added me to the list of users that can have remote access. Any ideas? Thanks in advanced.

Edit: If I'm reading this right, it seems as if when anyone else tries to join the server but me, I get the same error message in the server console as I got when I tried to login to the server console remotely and I typed in my password wrong. So could it be thinking that they are trying to connect to the console and denying them access?

Edit #2:

This is the error message that shows in the console when someone other than myself tries to connect. http://pastebin.com/aKq8nPi8

Also, the reason I get no error when logging into the server probably has something to do with the fact that I'm connecting with the internal IP instead of the external like everyone else is. At least that's my guess.