Android Parsing Data for android-L failed Unsupported major.minor version 51.0 Error

Have you just updated your Android Eclipse IDE (SDK) to API 21 (L Preview) then you may face the below error message when you load you start your Workspace.

‘Loading data for Android L (Preview)’ has encountered a problem.
Parsing Data for android-L failed
Parsing Data for android-L failed
Unsupported major.minor version 51.0

When you try looking at the "Graphic layout" for layout.xml file you would see nothing in the Palette view. The project target (Android L (Preview)) was not properly loaded and the error message window keeps popping every now and then.

If you compile your code against Android L-Preview then you require to have Java 7

Check for Java Development (JDK) version. For L Preview you must have JDK 1.7, JDK 1.6 would not work. If not then download JDK 1.7 and update JAVA_HOME for your windows Environment Variable or Appropriately for Linux of Mac OS X system.

Alternative Solution

You can complete your code against API levels below 20, change the targetSdkVersion in AndroidManifest.xml file below level 20.

Clean and Build your project and things should work fine.