Security Problem!

[Glookie]

i'm an old player from worlds 2-6 and really wanna play again, but every time i download it, their is a message the pops up and says http://puu.sh/dCCQJ/e5ba0adb86.png. if you don't wanna click on that it says "your security settings have blocked a self-signed application from running, i'm using java. it's their a way to fix this or another program i can use to play? please help!

[Ninijutsu]

viewtopic.php?f=4&t=35081