cURL error 60 on Add new Tweet

[tamerzg]

When trying to Add Tweet I am getting WSOD with this fatal error in log: GuzzleHttp\Exception\RequestException: cURL error 60: SSL certificate problem: unable to get local issuer certificate (see http://curl.haxx.se/libcurl/c/libcurl-errors.html) in GuzzleHttp\Handler\CurlFactory::createRejection() (line 187 of /drupal-8.1.8/vendor/guzzlehttp/guzzle/src/Handler/CurlFactory.php).