Include cannot bind when src contains parameters
<zk>
<window >
<button label="New page" onClick="append()">
<attribute name="onClick"><![CDATA[
include.setSrc(null);
include.setSrc("test2.zul?aa=bb");
//include.setSrc("test2.zul"); without param, works fine
]]></attribute>
</button>
<button label="Button Back" onClick="append()">
<attribute name="onClick"><![CDATA[
include.setSrc(null);
include.setSrc("test1.zul"); //NPE Include don´t exist

]]></attribute>
</button>
<include id="include" src=""/>
</window>
</zk>