Howto Solve: "Error: extension did not match expected (keystore)"

Some times when signing a PhoneGap Android Application, you run into this error:

Error: extension did not match expected (keystore)

Open cmd type: cd C:\java path\java\jdk7\bin

A command line solution is:

keytool -genkey -v -keystore yourappname.keystore -alias appnamealias -keyalg RSA -keysize 2048 -validity 10000

After that you will have an new release keystore for your application!