Error Message:

java.lang.ClassCastException: org.zkoss.reference.developer.mvvm.collection.model.Item
at org.zkoss.bind.converter.sys.RadiogroupSelectedItemConverter.coerceToUi(RadiogroupSelectedItemConverter.java:59)
at org.zkoss.bind.impl.LoadPropertyBindingImpl.load(LoadPropertyBindingImpl.java:74)
at org.zkoss.bind.impl.PropertyBindingHandler.doLoadBinding(PropertyBindingHandler.java:171)
at org.zkoss.bind.impl.PropertyBindingHandler.doLoad(PropertyBindingHandler.java:372)
at org.zkoss.bind.impl.BinderImpl.loadComponentProperties(BinderImpl.java:1802)
at org.zkoss.bind.impl.BinderImpl.loadComponent(BinderImpl.java:1779)
at org.zkoss.bind.impl.BinderImpl.loadComponent(BinderImpl.java:1782)
at org.zkoss.bind.impl.BinderImpl.loadComponent(BinderImpl.java:1782)
at org.zkoss.bind.BindComposer$BinderKeeper$Loader.load(BindComposer.java:468)
at org.zkoss.bind.BindComposer$BinderKeeper.loadComponentForAllBinders(BindComposer.java:450)
at org.zkoss.bind.BindComposer.doAfterCompose(BindComposer.java:174)

Reproducing Steps:

1. use the following code to reproduce the exception.

		<radiogroup selectedItem="@bind(vm.pickedItem)">
			<vlayout children="@load(vm.itemList)">
				<template name="children">
					<radio label="@load(each)" value="@load(each)" />
				</template>
			</vlayout>
		</radiogroup>

vm.pickedItem is an Item object. vm.itemList is List<Item> object.

public class Item {

	private String name;
}

extracted from :
https://zkbooks.googlecode.com/svn/trunk/devref/src/main/webapp/selection-radio.zul