Cannot to mount on /root/FLA_DHRS/SHRHZ006: Operation not permitted

That's not a Perl error, but an error generated from an external command.

Can't call method "sheets" on an undefined value at /var/www/cgi-bin/perldev/excel.cgi line 22.

That means that in $xls->sheets, $xls is undefined. $xls is whatever is returned by Spreadsheet::ParseExcel::Simple->read('/root/FLA_DHRS/SHRHZ006/7513.xls'); You don't check whether that returns an object or not.

Abigail