The method getImageDescriptor() report error in SphinxValidationUiActivator.java

The method org.eclipse.sphinx.emf.validation.ui.SphinxValidationUiActivator.getImageDescriptor(SphinxValidationUiActivator.IMG_OBJS_ERROR_PATH) can not return the image.

//get image by key public ImageDescriptor getImageDescriptor(String key) { Object url = getImage(key); if (url instanceof URL) { return getImageDescriptor((URL) url); } else { return null; } }