Fatal error: Uncaught exception 'Guzzle\Common\Exception\RuntimeException' with message 'The PHP cURL extension must be installed to use Guzzle.' in /home/www/web21/html/wp-content/plugins/timeline-express/lib/classes/usage-tracking/vendor/guzzle/guzzle/src/Guzzle/Http/Client.php:72 Stack trace: #0 /home/www/web21/html/wp-content/plugins/timeline-express/lib/classes/usage-tracking/vendor/keen-io/keen-io/src/Client/KeenIOClient.php(76): Guzzle\Http\Client->__construct('https://api.kee...', Object(Guzzle\Common\Collection)) #1 /home/www/web21/html/wp-content/plugins/timeline-express/lib/classes/usage-tracking/wp-plugin-usage-tracker.php(83): KeenIO\Client\KeenIOClient::factory(Array) #2 /home/www/web21/html/wp-content/plugins/timeline-express/lib/classes/class.timeline-express-admin.php(25): WP_Plugin_Usage_Tracker->__construct() #3 /home/www/web21/html/wp-content/plugins/timeline-express/lib/classes/class.timeline-express-admin.php(456): TimelineExpressAdmin->__construct() #4 /home/www/web21/html/wp-content/plugins/timelin in /home/www/web21/html/wp-content/plugins/timeline-express/lib/classes/usage-tracking/vendor/guzzle/guzzle/src/Guzzle/Http/Client.php on line 72