In LibreOffice Basic, how can I stop my macro crashing when a control is absent?

In a previous post I presented macro code to capture the contents of a text frame. I am trying to add error processing, the aim is to fail silently if anything is missing.

I now have this code fragment:

On Error GoTo End
try:
    
    oFrame = document.TextFrames
    if IsError(oFrame) or isNull(oFrame) then exit sub

    oField = oFrame.getByName("xxDocTitle") ‘ Exception here
    
    if IsError(oField) then exit sub
    if isNull(oField) or isNull(oField.String) or oField.String = "" then exit sub
    filename = oField.String & ".odt" 
Catch:
    ' Exit silently
end sub

it works if the text frame is empty but always produces an error dialogue if the frame is absent:

An exception occurred

Type: com.sun.star.container.NoSuchElementException

Message:.

Can I do anything to suppress the exception message?