WP Mail SMTP curl cert error

Replies: 0

I am getting the following error and have tried the steps below to resolve it.

Versions:
WordPress: 4.9.4
WordPress MS: No
PHP: 5.5.11
WP Mail SMTP: 1.2.5

Params:
Mailer: gmail
Constants: No
Client ID/Secret: Yes
Auth Code: Yes
Access Token: No

Server:
OpenSSL: Yes
PHP.allow_url_fopen: Yes
PHP.stream_socket_client(): Yes
PHP.fsockopen(): Yes
PHP.curl_version(): Yes

Debug:
cURL error 60: SSL certificate problem: unable to get local issuer certificate (see http://curl.haxx.se/libcurl/c/libcurl-errors.html)
Error while sending via Gmail mailer: cURL error 60: SSL certificate problem: unable to get local issuer certificate (see http://curl.haxx.se/libcurl/c/libcurl-errors.html)
cURL error 60: SSL certificate problem: unable to get local issuer certificate (see http://curl.haxx.se/libcurl/c/libcurl-errors.html)

I have downloaded cacert.pem and placed it in the directory D:\PHPCurlCert
I added the following line to php.ini: curl.cainfo = “D:\PHPCurlCert\cacert.pem”

Suggestions on what to try next?