If you are trying to do Survival Multiplayer, then you are using the wrong server software.
(goto http://minecraft.net/download.jsp and get the one from the bottom of the page)
If you meant to do classic/creative, then I dont know what to tell you, other than read the 'support' and 'server adminstration' sections and look for solutions, or just continue using the browser client.
I logged in.
When I connect through the website, no issues.
(goto http://minecraft.net/download.jsp and get the one from the bottom of the page)
If you meant to do classic/creative, then I dont know what to tell you, other than read the 'support' and 'server adminstration' sections and look for solutions, or just continue using the browser client.