Getting ClassNotFound when class is in the application when creating unmanaged threads or using java.util.Timer, or registering Message Listeners

Issue

We are getting a ClassNotFoundException for a class that is in the application when we create our own threads from the application.

java.lang.NoClassDefFoundError: com/jboss.examples/Example
  at com.jboss.examples.ExampleService.invoke(ExampleService.java:123)
  ...
  at com.jboss.examples.thread.ExampleThread$ExampleThreadRunnable.run(ExampleThread.java:123)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
  at java.lang.Thread.run(Thread.java:750)
Caused by: java.lang.ClassNotFoundException: com.jboss.examples.Example from [Module "deployment.application.ear.web.war" from Service Module Loader]
  at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:255)
  at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:410)
  at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:398)
  at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:116)
  ... 17 more