title: Maven dependency versioning and java.lang.NoClassDefFoundError
body: <p>I have a Java project X has dependency (in pom file) on project Y.</p>
  
  <p>I was modifying in Y and build X,Y with Maven tool then runing X (on JBoss) without problems.</p>
  
  <p>When I added new class in Y then building with Maven (without problems), then running X, it throws <code>java.lang.NoClassDefFoundError</code> for the new class.</p>
  
  <p>I think its a Maven dependency versioning or something like that ... I searched mainly at Google but nothing has effect... How to resolve this problem??</p>