"Disconnected by Server: BadPaddingException"

I have not opened up my Minecraft launcher for nearly a year. However, when I updated to Minecraft 1.6.2 and the new launcher recently, every server I attempt to connect to seems to have some kind of problem, leaving me with this every time I try to connect to any server:

I have checked and double checked every server and they are definitely up to date and my internet connection is working. I also guarantee you that my launcher is the official Minecraft launcher and I am playing online with a premium account.

Why is this issue cropping up? What does the text mean and how can I fix this?

Solution 1:

I've googled BadPaddingException and this is what it means: the wrong key was used to decrypt the data. It is an error for Minecraft to fix, so what you should do is report a bug to Mojang and they should fix it in later updates.