# 52145: Failed to authenticate with APNs

Log Level: ERROR

## Description

### Possible causes

* Unable to complete the TLS handshake with APNs.

### Possible solutions

* Verify that your certificate and private key are correct and can be used together.
* Verify that your certificate has not been revoked.
* If the problem persists, please contact [customer support](https://www.twilio.com/help/contact).