phpMyFAQ Fatal error

Uncaught exception: 'TypeError'

Message: 'phpMyFAQ\Strings::htmlentities(): Argument #1 ($string) must be of type string, null given, called in /usr/www/d3photography.com/faq/add.php on line 70'

Stack trace:

#0 /usr/www/d3photography.com/faq/add.php(70): phpMyFAQ\Strings::htmlentities()
#1 /usr/www/d3photography.com/faq/index.php(793): require('...')
#2 {main}

Thrown in '/usr/www/d3photography.com/faq/src/phpMyFAQ/Strings.php' on line 274