Internal Server Error: Invalid command '<IfVersion'

Symptoms

A website is displaying an internal server error, and the following error is logged to Apache's error log:

/home/username/public_html/.htaccess: Invalid command '<IfVersion', perhaps
misspelled or defined by a module not included in the server configuration

Description 

The mod_version Apache module must be installed to use the "<IfVersion" command in a .htaccess file.

Workaround

Use WHM >> EasyApache 4 to install the mod_version Apache module:

How to install an Apache module in WHM