If it is really dying without error, you should follow the Basic debugging checklist, especially points 2 and 4:

use Data::Dumper;
...
print Dumper \@wsl;
foreach $filename(@wsl)
    {
    warn "trying to open file '$filename'\n";
    open(FIN, $filename)  or die "Could not open file '$filename' $!";
    warn "successfully opened file '$filename'\n";
    while (my $row = <FIN>)
...
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I prefer to put filenames in configuration files¹, e.g. using Config::Tiny.

• The advantage of this approach is that you can put your filenames there totally unchanged, including backslashes, spaces and other special characters.
• Disadvantage: for characters outside the ASCII range you have to use the same encoding (binmode) as your editor (or whatever tool you use to put the filename into the config file).

¹ - obviously this is not feasible for the name of the configuration file itself…