Problem with Build Path > Configure Build Path > Order and Export

Hello,

When I try to add jar to the project with Build Path > Configure Build Path > Order and Export in Eclipse(eclipseme plugin) I get this message:

Building workspace has ecountered a problem.
Errors occurred during the build

Errors occurred during the build.
Errors running builder 'Preverification' on project 'HelloMap'.
org.eclipse.jdt.internal.core.JavaModel.getTarget(Lorg/eclipse/core/resources/IContainer;Lorg/eclipse/core/runtime/IPath;Z)Ljava/lang/Object;

I am a junior java programer and I don't know how to solve the problem. I waste so many time for this problem :(
I am trying to run HelloMap :)