network connection warning

since yesterday i get his message when i try to open up iTunes, and many more apps.



what do i do to prevent it from popping up again and what could of caused it?

 

fixed it by doing this


If you are experiencing this problem on your Mac, follow these simple steps to get rid of the Allow or Deny popups:

Go to the Applications folder and drag iTunes to the Trash. Don’t worry, your music, videos, and entire media library are not affected and will still be there. Only the iTunes software will be uninstalled.
Reboot or log out of your Mac. This step may or may not be necessary, but it certainly doesn’t hurt.
When you are logged back in, go to Apple’s website to download the latest version of iTunes.
Install iTunes. Do not import any songs or videos if it prompts you to do so.
All of your media should be right where you left it the first time your fresh installation of iTunes is opened. If you get another firewall popup asking to Allow or Deny incoming network connections, make your choice and that should be the last time you see it. Future iTunes launches won’t pester you anymore.