After installing ADT Plugin for Eclipse, I tried to make a new Hello world Android app.
But I met with the following error when I tried to open a new Android Application. I'm working with JDK 7.0 and JRE 7.0. I initially worked with JDK 6.0, but met with the same error, hence I uninstalled it and installed JDK 7.0 and changed the path settings respectively.
The error clearly is:
Loading data for Android L(Preview) has encountered a problem. Parsing data for Android L failed.Unsupported major.minor version 51.0.
My compliance levels are also changed to JDK 1.7 only. And I also changed my JRE compliance to 1.7.
I was facing the same problem on my Mac OSX and for me the problem was resolved by downloading and installing JDK 1.8 from Java SE Development Kit 8 Downloads. You just need to install(or update to) JDK 1.8 and restart the eclipse. That's it! Should work afterwards.