how check lifeless array vba macro

i wish check lifeless arrays. google gave me various solutions nonetheless zero worked. maybe i am requesting correctly.

function getboiler(byval sfile string) string
'email signature
    low fso object
    low ts object
    set fso = createobject("scripting.filesystemobject")
    set ts = fso.getfile(sfile).openastextstream(1, -2)
    getboiler = ts.readall
    ts.close
end function

dim filenameslist variant, i integer
' activate preferred startfolder filesearch
filenameslist = createfilelist("*.*", false) ' advantage record names
' performs filesearch, includes any subfolders
' donation result
' there signatures following stock sigstring
range("a:a").clearcontents
for i = 1 ubound(filenameslist)
    cells(i + 1, 1).formula = filenameslist(i)
next i

sigstring = filenameslist(3)

if dir(sigstring) <> "" then
    signature = getboiler(sigstring)
else
    signature = ""
end if

here filenameslist array empty, getboiler(sigstring) should called during all. filenameslist array empty, sigstring also lifeless calls getboiler() duty lifeless string. i an blunder during line

set ts = fso.getfile(sfile).openastextstream(1, -2)

since sfile empty. any proceed prevaricate that?