You can get remove the ClearButton
through the IsClearButtonVisible
property - just set it to False
. You can find more information about the common properties of the MaskedInput controls in our documentation.
However, I am not sure why you see the red border - it is usually an indicator of a failed validation. This is why I want to ask you to please share with us the definition of the control so that we can suggest how to get over the validation issue. Thank you in advance.
the Telerik team