Steps to Reproduce

<zk>
	<grid>
		<rows>
			<row>
				<timebox hflex="1" />
			</row>
		</rows>
	</grid>
</zk>

On mobile devices or Chrome (simulate iPad)

Current Result

Error code 3: ZK error, after mounting.

Uncaught TypeError: a._scrollbar.hasVScroll is not a function
at zjq.hasVScroll (VM692 zk.wpd:265)
at Object.fixFlex (VM692 zk.wpd:570)
at b.onSize (VM692 zk.wpd:569)

Expected Result

No error

Debug Information

https://github.com/zkoss/zk/blob/v8.5.2.1/zk/src/archive/web/js/zk/dom.js#L800
This method expects a zul.Scrollbar instance.

But not all _scrollbar is an instance of it.

Workaround

Avoid using flex on these components