Linux Script problem after upgrade to 9.5 SP4

Question

After our upgrade a script that we had to monitor NTP stratum no longer works. Here is the error code:

Testing on node Test-Linux: failed with 'Undefined' status

Invalid script return code: 127

Here is a copy of the script that we execute:

#!/usr/bin/perl

$grepstratum = `/usr/sbin/ntpq -c rv | grep -i stratum`;
chomp($current_time = `date`);

if ($grepstratum =~ m/stratum=(\d+)/) {
   if ((0 < $1) && ($1 <= 9)) {
       open (STDOUT);
       print "0
";
       print "Statistic: $1
";
       print "Message:  $current_time  Stratum is $1
";
       close (STDOUT);
       exit(0);
   } else {
       open (STDOUT);
       print "1
";
       print "Statistic: $1
";
       print "Message:  $current_time  Stratum is $1
";
       close (STDOUT);
       exit (1);
   }
};

Nothing has changed except for the upgrade. Appreciate any responses. Thanks