Same error here =/
Fatal error: Uncaught GuzzleHttp\Ring\Exception\RingException: cURL error 60: SSL certificate problem: self signed certificate in certificate chain in C:\inetpub\copyexpress.ca\wp-content\plugins\constant-contact-forms\vendor\constantcontact\guzzlehttp\ringphp\src\Client\CurlFactory.php:127 Stack trace: #0 C:\inetpub\copyexpress.ca\wp-content\plugins\constant-contact-forms\vendor\constantcontact\guzzlehttp\ringphp\src\Client\CurlFactory.php(91): GuzzleHttp\Ring\Client\CurlFactory::createErrorResponse(Array, Array, Array) #1 C:\inetpub\copyexpress.ca\wp-content\plugins\constant-contact-forms\vendor\constantcontact\guzzlehttp\ringphp\src\Client\CurlHandler.php(96): GuzzleHttp\Ring\Client\CurlFactory::createResponse(Array, Array, Array, Array, Resource id #136) #2 C:\inetpub\copyexpress.ca\wp-content\plugins\constant-contact-forms\vendor\constantcontact\guzzlehttp\ringphp\src\Client\CurlHandler.php(68): GuzzleHttp\Ring\Client\CurlHandler->_invokeAsArray(Array) #3 C:\inetpub\copyexpress.ca\wp-content\plugins\constant-contact- in C:\inetpub\copyexpress.ca\wp-content\plugins\constant-contact-forms\vendor\constantcontact\guzzlehttp\guzzle\src\Exception\RequestException.php on line 51