📖 How to Fix cURL Error 28 on License Activation

Sometimes, when users try to connect or activate their license, they may encounter a “Connection Timeout” error. There’s no need to worry; this usually happens due to certain limitations on your server. These settings can be reviewed and adjusted to successfully activate your license key and unlock full access to the Instant Knowledge Base premium features.

Error Message:

cURL error 28: Connection timed out after 10001 milliseconds

This error occurs when your WordPress site tries to connect to our server, but the connection attempt fails because it takes too long to respond.

What Does This Mean?

This is a timeout error, not a security or SSL error.

• It does not mean the license is invalid.
• It does not mean the connection is insecure.
• It means your site couldn’t establish a connection to the license server within the allowed time (10 seconds).

Why This May Happen

• The server hosting your site is blocking outgoing connections.
• The license server is temporarily slow or unreachable.
• Firewall, DNS, or network issues are interfering.
• A security plugin or setting is delaying or blocking HTTP requests.
• Server settings like max_execution_time or cURL timeout are too low.

Steps to Resolve the Issue

1. Test Outbound Connectivity

You can run a connection test using the following PHP code:

<?php
$response = wp_remote_get('https://your-license-server.com', ['timeout' => 15]);

if (is_wp_error($response)) {
    echo 'Error: ' . $response->get_error_message();
} else {
    echo 'Success! HTTP Code: ' . wp_remote_retrieve_response_code($response);
}

Replace the URL with your actual license server URL. Upload this as a PHP file on your server and open it in your browser.

If it times out or fails, your server cannot reach the license server — and the issue is confirmed.

2. Contact Hosting Provider

Share the error and ask your host:

“Can you confirm if outgoing cURL or HTTP requests are allowed to external domains, particularly to our license server? We’re getting a cURL error 28 (timeout), and need to ensure nothing is blocking or slowing these requests.”

They should check:

• Firewall or ModSecurity rules
• Outbound port and domain restrictions
• Server resource limits

3. Temporarily Disable Security Plugins

Deactivate any security plugin that is installed on your site. Go to Plugins>Installed Plugins to check. Check and deactivate any of the following if installed:

• Wordfence
• Sucuri Security
• iThemes Security
• All-in-One Security (AIOS)

Retry the license activation. These plugins sometimes block or delay outbound API calls.

4. Check Server PHP & cURL Configuration

Make sure your server has:

Setting	Recommended Value
allow_url_fopen	ON
max_execution_time	≥ 30
memory_limit	≥ 128M
PHP cURL	Enabled with HTTPS support

You can check this in a phpinfo() page or ask your host.

✅ License Works Elsewhere	The license server is online and functional
❌ Fails Only On One Site	Hosting/network issue on that site
❗ Timeout Error	Your site couldn’t connect in time

Still Need Help?

If you’ve tried the steps above and the issue persists, reach out to your hosting provider or Instant Knowledge Base support team. Be sure to include:

• The full error message
• A copy of the PHP connection test result
• Confirmation that the license server is up