Hi everyone,

Could you please help us solve a small problem?
We have overridden the Button component (https://www.zkoss.org/wiki/ZK_Component_Reference/Essential_Components/Button).
It is a part of the package "ut".

Sometimes when a zul page is rendered (a page that has an instance of the overridden Button) we get this error - see screenshot 1.

This error is rare.

If the error occurs, the ut.wpd script doesn't contain "ut.Button".
But zk.wpd contains the widget element - see screenshot 2.

What causes this error?
Thanks in advance!