Description: Eclipse can not build the project, because project is missing default builder. It happens most of the time when checking out project from SVN or CVS.
Solution: You need to add the default Java builder into .project file.
Verify that following lines are present in .project file of the eclipse project. If it is not present in the file, copy it from here and save the file.
Adding default Java builder
That’s it! select the Java builder from project propertiese > builder, clean and build the project again. you should be able to build the project now.