NoSuchMethodException for methods using custom data type

Whenever dynamically loading a class using the URLClassLoader I get a NoSuchMethodException when trying to execute a method with a custom data type as a parameter. It finds methods with standard types like String and int but not the custom type.

Loaded Class:

public void execute(ProcessingData data){

    System.out.println("entered execute(ProcessingData data");

Calling Class:

URLClassLoader loader =
        new URLClassLoader(new URL[] {new File(alg.getPath()).toURI().toURL()}, AlgorithmLoader.class.getClassLoader());

    // Load class into memory
    Class<?> algClass = Class.forName(className, true, loader);
    logger.logInfo("Loaded class. Attempting to invoke execute(data) on aircraft: "+ data.getFlightData().getAircraftId());
    Method processMethod = null;

    try {
      Object obj = algClass.newInstance();
      processMethod = algClass.getDeclaredMethod("execute", ProcessingData.class);
      processMethod.invoke(obj, data);
    } catch (final NoSuchMethodException exception) {
      logger.logInfo(exception.toString());
    }
    loader.close();