I've taken notice on how some users have been having problems with classic minecraft and the World of Minecraft Client. I also noticed that they have Java 7 JRE installed which is causing problems with connecting and etc. To solve this issue, you'll need to uninstall Java 7 and get Java 6 JRE (Get the Latest Version, check with http://java.com/en/download/installed.jsp to make sure you have the latest java 6 downloaded, double check you have Java 6,(Windows - Windows-R, cmd.exe, java -version | Linux - Open a terminal/command window, java -version | Mac - open a command window, type java -version).
Common Errors -
"org.lwjgl.LWJGLException: Could not create context"
"Minecraft failed to start" "java.lang.ArrayIndexOutOfBoundsException: 0
"Minecraft failed to start Java.lang.IllegalAgrumentexeption:input==null!* - The above picture will occur on any server you select!
***Even if you have Java 6 installed with Java 7, you'll need to uninstall Java 7!!!!
To get Java 6 JRE - Windows & Mac
- http://www.oracle.com/technetwork/java/javase/downloads/jre-6u32-downloads-1594646.html
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Running Linux?
If you would like sun java use the above method, if sun java doesn't like to work on your system, use openjdk6