This gist may help others who have a Netgear Stora that encounters the issue "Error message: at /var/www/admin/update.pm line 346"

Fix_Netgear_Stora.sh

#!/bin/bash

# This is the contents of the updated script:
NEW_SCRIPT=$(cat << EOF
package setup_update;
sub process {
    return 'success';
}
sub display {
    my $vars = shift @_;
    my $template = shift @_;
    $$vars{'name'} = $name;
    die 'Template error: ' . $template->error . "\n" unless $template->process('setup_update.html', $vars);
}
'???';
EOF
)

# Make a backup of the existing file just in case:
cp /var/www/admin/setup_update.pm /var/www/admin/setup_update.pm.bak

# Dump the new script into the old location. Note: this doesn't have to be compiled/turned into bytecode. 
# Plain-text perl scripts can be relablled .pm and used as modules.
echo "$NEW_SCRIPT" > /var/www/admin/setup_update.pm

The update server may go offline, or the update server components (MySql) may fail. As a result, the following error message will appear when attempting to reset the Stora:
Error message: at /var/www/admin/update.pm line 346

The above gist effectively zeroes-out the update check and bypasses the actual scanning of the update server.

I was running into this issue on my own Stora and found a forum post describing the root cause, so I created the above script to (hopefully) help others. Here's a link to the forum thread:
https://community.netgear.com/t5/Stora-Legacy/Stora-Error-Message-on-Setup/m-p/1573609/highlight/false#M9412

Note to self: if I ever end up needing this again because I've reset my Stora, don't forget to disable uPnP (!) because it's on by default (!?!?!)