title: java.lang.NoClassDefFoundError: occurs after multiple uses of a program
body: <p>I have a service that runs from a docker container which runs just fine for about an hour or so, and then suddenly throws a <code>java.lang.NoClassDefFoundError</code>. After reading up on these errors it seems it is often an issue in initialization. However, my service runs just fine at first -- including using the class that suddenly can't be found! </p>
  
  <p>In fact this particular class needs to be initialized in order for the service to start correctly. This is a multithreaded application running on Spring.</p>
  
  <p>What are some reasons for a class to go missing after being used?</p>