> ## Documentation Index
> Fetch the complete documentation index at: https://moengage-user-guide.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Why Does the "APNS Client Connection" Error Occur?

## Problem

When sending push notifications in iOS to a reachable user, the "APNS Client Connection" error occurs.

## Explanation

This error can happen for the following reasons:

* The APNS certificate linked to the PEM file on the MoEngage dashboard has expired or been revoked.
* The AuthKey has been revoked on the Apple Developer account.

## Solution

Create a new PEM file or AuthKey and upload it on the MoEngage dashboard.