Fatal error: Uncaught Error: Interface 'JsonSerializable' not found in /home/hkdpaacomb/domains/hkdpaa.com/public_html/vendor/sendgrid/sendgrid/lib/helpers/mail/Mail.php:15 Stack trace: #0 /home/hkdpaacomb/domains/hkdpaa.com/public_html/vendor/composer/autoload_real.php(66): require() #1 /home/hkdpaacomb/domains/hkdpaa.com/public_html/vendor/composer/autoload_real.php(56): composerRequire3d224562b4bd0d9a0cc16991d99b628a('9dda55337a76a24...', '/home/hkdpaacom...') #2 /home/hkdpaacomb/domains/hkdpaa.com/public_html/vendor/autoload.php(7): ComposerAutoloaderInit3d224562b4bd0d9a0cc16991d99b628a::getLoader() #3 /home/hkdpaacomb/domains/hkdpaa.com/public_html/index.php(5): require('/home/hkdpaacom...') #4 {main} thrown in /home/hkdpaacomb/domains/hkdpaa.com/public_html/vendor/sendgrid/sendgrid/lib/helpers/mail/Mail.php on line 15