The 1st case: Steps to Reproduce

1. load the page

    <tabbox height="100%" >
    <custom-attributes org.zkoss.zul.client.rod="true"/>
        <tabs>
            <tab label="1st"/>
            <tab label="spreadsheet"/>
        </tabs>
        <tabpanels>
            <tabpanel hflex="1" vflex="1">
                first
                <button label="invalidate spreadsheet" onClick="ss.invalidate()"/>
            </tabpanel>
            <tabpanel vflex="1" hflex="1">
                test
                <spreadsheet id="ss" hflex="1" vflex="1"
                             src="/WEB-INF/books/blank.xlsx"
                />
            </tabpanel>
        </tabpanels>
    </tabbox>

2. select 2nd tab to make spreadsheet rendered
3. select the 1st tab
4. click the button to invalidate spreadsheet

Current Result

1. js error
zss.wpd:35600 Uncaught TypeError: Cannot read properties of undefined (reading 'height')
at zss.wpd:35600:75
at doAfterMount (zk.wpd:26214:4)
at mtBL1 (zk.wpd:26167:3)
at mtBL0 (zk.wpd:26159:3)
at mtBL (zk.wpd:26124:3)
at doEnd (zk.wpd:25590:4)
at Function._zkf (zk.wpd:25630:4)
at zss.wpd:43456:13
at doEnd (zk.wpd:25590:4)
at Function._zkf (zk.wpd:25629:4)

2. the scrollbar doesn't work

Expected Result

1. no js error
2. scrollbar should work

Debug Information

1. In zss.ScrollPanel.$init(), self._scrollbar.axis.x.scrollbar.el.parentElement.getClientRects() returns an empty collection because self._scrollbar.axis.x.scrollbar.el.parentElement is invisible
2. If we can find a good way to initialize the scrollbar when keikai becomes visible, that's fine. If not, just leave it as low priority.

Workaround

<custom-attributes org.zkoss.zul.client.rod="true"/>

The 2nd case: Steps to reproduce

1. load 14754.zul
check developer tool > Console

Current Result

the same error as the 1st case

Debug info

this is a special use case that keikai needs to render itself under its parent element is invisible

Workaround

• keikai-573-0128.js: get scrollbar parent element's height later after keikai is visible.