[Plugin: W3 Total Cache] Amazon CDN – Test fail, but works as CDN

Please submit a bug submission request from the support tab of the plugin, there are no obvious causes for this error.

I’ve received the same error in trying to configure cloudfront CDN option. I’ll submit, but if anyone has solved this I’d appreciate the insight.

Is cURL for PHP installed?

I’m getting the “Unable to list distributions” error also.

It’s a IIS-6 server with curl installed.

The error message for the request was “could not connect to host”. Could be a problem making SSL requests on a Windows server? See the comments — https://php.net/manual/en/ref.curl.php

@sam_a unfortunately, I don’t officially support IIS, although I’m aware of successful installations. If you submit a bug submission form I will see if I can find any obvious issues.

I haven’t been able to test it, but some Googling suggests setting CURLOPT_SSL_VERIFYHOST or CURLOPT_SSL_VERIFYPEER or both to false might work on IIS.

Did you apply those changes yourself? Any luck?

I did get a successful connection after setting CURLOPT_SSL_VERIFYPEER to false, but I have a hunch that updating curl’s certificates might be the proper fix.

So I set CURLOPT_VERBOSE => true and first tried CURLOPT_SSL_VERIFYPEER => true:

* About to connect() to www.google.com port 443 (#0)
*   Trying 74.125.67.103... * connected
* Connected to www.google.com (74.125.67.103) port 443 (#0)
* SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
* Closing connection #0

And then I tried CURLOPT_SSL_VERIFYPEER => false

* About to connect() to www.google.com port 443 (#0)
*   Trying 74.125.67.103... * connected
* Connected to www.google.com (74.125.67.103) port 443 (#0)
* SSL connection using RC4-SHA
* Server certificate:
[…]
* SSL certificate verify result: unable to get local issuer certificate (20), continuing anyway.

There’s an option to ignore certificates with curl btw.

I had the same problem using php-fpm & nginx. turned out i hadn’t installed the PHP openssl extension so W3TC was reverting to https:// for cloudfront, which doesn’t accept connections.

I see.