Black Raven Dragoons

tried to log on today and got an invalid server key again......


Minecraft Why You No Work?
(屮ಠ益ಠ)屮

It's not a problem with Josh's server. It's a problem with the Minecraft server software that's a known issue, but there's no fix yet because Mojang is still in Nevada and will be until Monday.

The only fix is to close your client completely and try again. It appears to cache the server response, so once it starts generating that error, you probably won't ever connect. Also, sometimes clicking the "direct connect" button and entering in the server address might work. It, too, seems to cache the results, though.

TL;DR: Try and try again.