Could not connect to update server


An error on the ‘Custom Fields -> Updates’ page will appear when it is not possible for your website to connect to the ACF server. If you see an error, you will not be able to activate your license or download updates until the issue is fixed.

Please find some possible error messages below and be sure to contact our support team for any help.

Error connecting to update server (cURL error 51: SSL *

This problem is caused by a mixture of our ACF web host’s server setup (siteground) and your server’s SNI/TLS settings. The issue can be solved either of the following:

1. Web host: If possible, ask your web host to update the cURL version to one which supports SNI.
2. WP: Use the https_ssl_verify filter to avoid the SSL detection (code snippet below)


add_filter( 'https_ssl_verify', '__return_false' );

Error connecting to update server (meta 0;/.well-known/captcha/)

Full error message

<html><meta http-equiv="refresh" content="0;/.well-known/captcha/"></meta></head></html>

This error suggests the HTTP connection was blocked. Please contact your web host to find your outgoing IP address (different from your normal IP address) and contact our support team with all available info.

Error connecting to update server (<)

This error message is a broken version of the above ‘.well-known/captcha’ issue. Please see instructions above.


This issue suggests there is a firewall or other ‘block’ refusing the outgoing connection to our update server. Please contact your web host and notify them that your website is unable to connect to the ACF server preventing plugin updates. Ask them to test a connection to the following URL and review the response. This will show any problems with PHP settings or internal firewalls.

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