Source locator does not exist: org.eclipse.jdt.debug.ui.javaSourcelocator

Hi

I got a above the error When start the debugging in my NWDS.

Source locator does not exist: org.eclipse.jdt.debug.ui.javaSourcelocator

Solutions is Reinstalling the NWDS , that option is not a good solution(choose any another options)

Please any advices... How to fix ?

Thanks

Srini