netbeans 6.5 giving java.lang.NullPointerException suddenly when starting

I use Netbeans for coding in Ruby. Since yesterday, netbeans is suddenly not starting normally. It gives a java.lang.NullPointerExc开发者_运维技巧eption and then after i cancel the popup box, it loads after some time ( taking much longer than it used to earlier ). I don't have much idea what is going wrong. I use Netbeans6.5.

From the logs figured out that the error was because of some problem with loading the mercurial module for VCS. Removed that plugin from netbeans and things are up and running again.