HOW TO FIX- "Missing keys.plist data for this build"- Redsn0w Error

Step 1- Open up redsn0w and select extras.

Step 2- In the menu that follows, select "Select IPSW".

Step 3- browse to where you have saved an IPSW of iOS 6. (Even if you're jail breaking iOS 6.1)

Step 4- Let Cydia do its magic, and you're good to go.