HTML files inside of the cgi-bin directory show a 500 error

Symptoms

When attempting to view an HTML file that  is placed inside of the cgi-bin directory of a cPanel account, a 500 error is seen in the browser, and a 500 error is logged to the Apache error log.

Description 

The cgi-bin directory is a special directory that only allows CGI scripts and other related files (such as txt files) to be viewed from it.

HTML files cannot be viewed from the cig-bin directory.

Workaround

You can place your HTML files outside of the cgi-bin directory, and then link to any CGI scripts within the cgi-bin directory as needed.