Why is the "Create alert rule..." missing for this grid?

Someone else on my t开发者_运维问答eam has created a form - for some reason the Grid control does not have the "Create alert rules..." option in it's context menu.

I can't see what the difference is between this grid/form and others that we have created that do have this in their context menu.

Does anybody know why it would be missing?

It can be missing because the form window type is Popup or the form frame style is other than Standard. The rules are specified in \Classes\EventBuildValidAlertFields\validate:

public boolean validate()
{
    ;
    if (!formRun                            ||
        !formDataSource                     ||
        !formDataSource.cursor().TableId    ||
         formRun.design().windowType() == FormWindowType::PopUp ||
         formRun.design().frame()      != FormFrame::Standard
        )
    {
        return false;
    }
    return true;
}

The Frame property was set to dialog. If anyone can tell me why, I might mark them as answer.