My imported eclipse project gives error the project was not build since the build path is incomplete. Cannot find the class file for java.lang.object <p>i have imported a existing project to eclipse but it gives errors for java files only i have set libraries i have also set window>preferences>installed jres.BUt the problem is not solved. The error message is the project was not build since the build path is incomplete. Cannot find the class file for java.lang.object. Fix the error. <a href="http://i.stack.imgur.com/4upHD.png" rel="nofollow">error screenshot</a></p>