Bug 17256 Exception due to bug 17208
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/UpdateValueStrategy.java
if (dataTypeValidator == null) {
			throw new BindingException(
					"No IValidator is registered for conversions from " + fromType + " to " + toType); 
		}
		return dataTypeValidator;
	}
	/**
	 * 
	 * @param source
	 * @param destination
	 */
	protected void fillDefaults(IObservableValue source,
			IObservableValue destination) {
		Object sourceType = source.getValueType();
		Object destinationType = destination.getValueType();
		if (provideDefaults && sourceType != null && destinationType != null) {
			if (afterGetValidator == null) {
				afterGetValidator = createValidator(sourceType, destinationType);
			}
			if (converter == null) {
				setConverter(createConverter(sourceType, destinationType));
			}
		}
		if (converter != null) {
			if (sourceType != null) {
				checkAssignable(converter.getFromType(), sourceType,
						"converter does not convert from type " + sourceType); 
			}
			if (destinationType != null) {
				checkAssignable(converter.getToType(), destinationType,