Since FileMaker PHP APIs have several compatibility issues with latest PHP versions, I readapted the library to work with PHP 7.1.13 (I'm using php-osx).
Just copy-paste these files into your project replacing the old library (if you had one).
Then include in your project:
require_once("path/to/FileMaker.php");
And use it:
$fm = new FileMaker($database, $host, $username, $password, $options);
Hope you enjoy!