An Update Message Validation Issue notice may display at Utilities > Update WHMCS with the following message:

The Automatic Updater utility can display important messages before initiating the update process. A digital cryptographic signature protects them. This message indicates that the cryptographic validation is failing.

There are four potential causes of this:

1. The CA bundles are out of date and the system cannot validate the certificate.
2. OpenSSL is out of date.
3. A PHP configuration is causing the cryptographic validation to fail.
4. Your server is the target of a Man-in-the-Middle (MITM) attack.

To resolve this issue:

1. Go to Utilities > Update WHMCS and click Check for Updates. This will cause WHMCS to reevaluate the available updates and may complete the cryptographic validation.
2. Ensure that OpenSSL is up to date on your server. Work with your server administrator or hosting provider to make this change. After updating OpenSSL, repeat step 1 above.
3. Ensure that the root CA bundles on your server are up to date. After updating the root CA bundles, repeat step 1 above. For more information on updating root CA Bundles on your server, see Troubleshooting a File could not be downloaded error.

If the problem persists after performing these steps, WHMCS support can examine your PHP information for known problematic PHP settings or check for a MITM attack.