The attachment contains five small files (few lines each) with messy dependencies. When loaded from source, beginning with BallCellDef, it generates the stack trace below. The src folder has an example that attempts the load and generates the errors. When loaded from .class files, all is well: the problem only arises when there are no class files there. Exception in thread "main" java.lang.LinkageError: duplicate class definition: org/ccneuro/cell/compact/WkItemStruct at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:620) at java.lang.ClassLoader.defineClass(ClassLoader.java:465) at org.codehaus.janino.JavaSourceClassLoader.defineBytecode(JavaSourceClassLoader.java:358) at org.codehaus.janino.JavaSourceClassLoader.defineBytecodes(JavaSourceClassLoader.java:343) at org.codehaus.janino.CachingJavaSourceClassLoader.findClass(CachingJavaSourceClassLoader.java:195) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at java.lang.ClassLoader.loadClass(ClassLoader.java:251) at BallCellTest.main(BallCellTest.java:33)