Hello Yurii,

Thank you for reporting this. A possible solution is to manually modify the elements in the dialog. In the ConditionalFormattingFormShown event, we can get the form and modify its size and element position. In the following example, I will demonstrate how to extend the size of the form:

rivate Sub ConditionalFormattingFormShownEventHandler(sender As Object, e As EventArgs)
    Dim conditionalFormattingForm = TryCast(sender, ConditionalFormattingForm)
    If conditionalFormattingForm IsNot Nothing Then
        conditionalFormattingForm.Size = New Size(590, 641)
        conditionalFormattingForm.AutoSize = False
    End If
End Sub

Regards,
Dinko | Tech Support Engineer
Progress Telerik