...
#open(OUT, ">${pathName}html") or die "Couldn't open file file.txt, $!
+";
...
print OUT $line;
...
[download]

Perl would warn you about this if you used warnings resp. run your script with -w - you print to a filehandle that was never opened.

You haven't told us how your program fails exactly, but this might be one problem that makes it behave in a way you did not intend.