Android : Android - Eclipse project making and R file error

I'm having issue with Eclipse and I work in android. This issue happens when I create a new project and when I click finish, It auto generates the project without R file and The project creating window doesn't closes and I have to close it. I have many old projects which work fine(Until now) and the issue is only coming when I make a new project. I also get a error in Styles.xml file saying that "Error retrieving parent for item: No resource found that matches the given name 'Theme.AppCompat.Light'". When I press CTRL+RightClick onto R file then it takes me to a window which says "Source Not Found". If you have any solution for this, Please post your answer under this question. Thank you!