Internal Server Error (500) errors are typically, something wrong in the syntax of your script. Most often you should check to make sure you have the path to PERL correct. Currently we are running Perl5 on our servers.
The correct path to PERL is: #!/usr/bin/perl
Here are the correct paths to the common server resources that CGI scripts often require:

Perl version 5.006001: /usr/bin/perl
Absolute path for your files/scripts: /home/username/public_html/
Absolute cgi-bin path: /home/username/public_html/cgi-bin/
Sendmail: /usr/sbin/sendmail
Date: /bin/date
Java: /usr/bin/java
Whois: /usr/bin/whois
Python: Python: /usr/bin/python

Other most common reasons are:

• Wrong sysntax in your cgi script
• Wrong file permission, chmod 777 world read, write execute is most common error. Try chmod to 755
• Wrong File path. See correct format above.
• Cgi Script was not uploaded in ASCII mode.