Hi Ihardtke,

You may disable this prompt by hooking into the BeforeRowsDeleted event handler of the UltraGrid and access the DisplayPromptMsg property exposed from within the event arguments, you will need to set this property to false.

Example:

void ultraGrid1_BeforeRowsDeleted(object sender, BeforeRowsDeletedEventArgs e)
        {
            e.DisplayPromptMsg = false;
        }

If you have any further questions, please let me know.

Sincerely,
Chris K
Developer Support Engineer
Infragistics, Inc.
www.infragistics.com/support

How to get the latest service release - Infragistics Community

Upon further investigation, it looks like this is a bug in the DotNet framework.The issue has been reported to Microsoft here:

WinForm dialogs displayed differently by *.vshost.exe and *.exe using VS 2012 when FormBorderStyle set in form codebehind | Microsoft Connect

There's nothing we can do about it, but the good news is that it only happens when the Debugger is attached, so it will not affect your clients using your app.