You already have 2 active push profiles for this application/environment. You'll need to revoke an old certificate to make room for a new one
This happen when you request more than 2 updates/year.
To make room for a new certificate:
1. Go on https://developer.apple.com/account/
2. Click on Certificates, Identifiers & Profiles
3. Select the oldest Apple Push Service and click on Revoke
4. Go back on your WordPress backoffice and Request an update