You had the birth certificate but lost the original one, kept a photocopy or a scan, and tried to request a birth certificate extract, only to be told no record is found for unknown reason. That moment is challenging to accept and there is not much choices left.
And looking back, it does not mean your birth was never registered. Often, it means the copy extract procedure can not be completed with the record access currently available. Now, you might consider to apply birth certificate in Vietnam using the re-registration procedure.
