Thank For the response Yudi. The Solution Provided is working.

Glad to know that the approach helps.

Should you need further assistance or run into any problems regarding our controls, feel free to post it into our forum. We would be happy to assist you again.

I started my investigation by creating a simple WebApplication containing WebGrid then added confirmation alert oncellclick event of WebGrid.

Per my test, the reported problem doesn't persist. When the confirmation alert appear, after click on OK on alert, the grid doesn't crash.

Please find my project in the attachment and let me know if you find anything that I might miss during my attempt to reproduce the problem.

Please find attachment, Treeview_test_Modified.zip, which containing the modified sample to make it work with WebTreeView.

The WebTreeView sample implements advanced load-on-demand scenario for better performance. It allows you to add TreeViewNodes based on retrieved data.

Please have a look at the modified sample and let me know your response.

Thank you for the sent video. I was able to reproduce the problem after carefully following the steps shown in the video.

This problem has been forwarded to WebGrid development team to be investigated further. The report has been filed under ASPNET-410.

I will keep you informed with any news I heard from the team related to ASPNET-410.

From the screenshot, the error happen on GetTranslatedString function of WebGrid_Context.js. One of the events that trigger this function is: when AutoFilterSuggestion is enabled (WebGrid - LayoutSettings - AutoFilterSuggestion) and user right-click on WebGrid column header.

The error happen because h is undefined or null. Since h is the parameter passed by following expression (from GetBasicFilterColumns): d.GetString(b + f[e].Name.substring(3))

The above should expression should return something like: "Equals {0}".

In my opinion, the error might happen if ISGetObject("WebGrid1").GetString("ContextMenu/FilterSuggest/ET") returns undefine or null.
*Please note that the "ET" in string "ContextMenu/FilterSuggest/ET" might vary with: ET, NET, Contain, NotContain, LTET, GTET, and so on.

If you are using custom localization for your WebGrid, please ensure that the xml node under "FilterSuggest" is not left empty/blank.

<Localization culture="default" description="Default Language">
  ...
  <ContextMenu>
    ...
    <FilterSuggest>
      <ET>Equals {0}</ET>
      <NET>Does Not Equal {0}</NET>
      <Contain>Contains {0}</Contain>
      <NotContain>Does Not Contain {0}</NotContain>
      <LTET>Less Than or Equal To {0}</LTET>
      <GTET>Greater Than or Equal To {0}</GTET>
      <OnBefore>On or Before {0}</OnBefore>
      <OnAfter>On or After {0}</OnAfter>
      <Checked>Is Checked (True)</Checked>
      <NotChecked>Is Not Checked (False)</NotChecked>
      <Tomorrow>Tomorrow</Tomorrow>
      <Today>Today</Today>
      <Yesterday>Yesterday</Yesterday>
      <NextWeek>Next Week</NextWeek>
      <ThisWeek>This Week</ThisWeek>
      <LastWeek>Last Week</LastWeek>
      <NextMonth>Next Month</NextMonth>
      <ThisMonth>This Month</ThisMonth>
      <LastMonth>Last Month</LastMonth>
      <Past>Past</Past>
      <Future>Future</Future>
      <Blank>Blank</Blank>
    </FilterSuggest>
    ...
  </ContextMenu>
  ...
</Localization>

Hope this helps.