steps to reproduce

1. load the attached file

result

Uncaught TypeError: Cannot read property 'range' of null
zss.MainBlockCtrl.zk.$extends.loadForVisible @ zss.wpd:24
zss.SSheetCtrl.zk.$extends._resize @ zss.wpd:37
(anonymous function) @ zss.wpd:37
zss.SSheetCtrl.zk.$extends.doSSInitLater @ zss.wpd:37d @ zss.wpd:37(anonymous function) @ zss.wpd:37setTimeout (async)d @ zss.wpd:37zss.SSheetCtrl.zk.$extends.doSheetSelected @ zss.wpd:37zss.Spreadsheet.zk.$extends.$define.sheetId @ zss.wpd:2(anonymous function) @ zk.wpd:9897zk.copy._set2 @ zk.wpd:10331zk.Widget.zk.$extends.set @ zk.wpd:15568zAu.cmd1.setAttr @ zk.wpd:20279doProcess @ zk.wpd:19292doCmdsNow @ zk.wpd:19532zAu._doCmds @ zk.wpd:19780afterResponse @ zk.wpd:19424onResponseReady @ zk.wpd:19421XMLHttpRequest.send (async)ajaxSendNow @ zk.wpd:19484zAu.sendNow @ zk.wpd:19938(anonymous function) @ zk.wpd:19463setTimeout (async)ajaxSend2 @ zk.wpd:19463ajaxSend @ zk.wpd:19457zAu.send @ zk.wpd:19698zk.Widget.zk.$extends.sendAU @ zk.wpd:17069zk.Object.$supers @ zk.wpd:10655zss.Spreadsheet.zk.$extends.sendAU_ @ zss.wpd:2zk.Widget.zk.$extends.fireX @ zk.wpd:17048zk.Widget.zk.$extends.fire @ zk.wpd:17077zss.SheetSelector.zk.$extends.doSelectSheet @ zss.wpd:36zss.SheetSelector.zk.$extends.onSelectSheet @ zss.wpd:36(anonymous function) @ zk.wpd:10582zk.Widget.zk.$extends.fireX @ zk.wpd:17029_fireClick @ zk.wpd:14907zk.Widget.zk.$extends.doClick @ zk.wpd:17211zk.Object.$supers @ zk.wpd:10655zul.Widget.zk.$extends.doClick_ @ zk.wpd:22253zk.Object.$supers @ zk.wpd:10655zul.tab.Tab.zk.$extends.doClick_ @ zul.tab.wpd:910zk.Object.$supers @ zk.wpd:10629zss.SheetTab.zk.$extends.doClick_ @ zss.wpd:36_doEvt @ zk.wpd:18762(anonymous function) @ zk.wpd:18958jQuery.event.dispatch @ zk.wpd:5162elemData.handle @ zk.wpd:4833

debug info

• Notice Excel table has 6 options including a header row, please consider them
  
• if a table without a header row appears in the first sheet, it will block the whole rendering.