Workaround for this certificate issuer is not valid after iOS registers a remote push message certificate

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We need to register a related certificate when we write an app for remote push messaging, and we can first create an app ID on the certificates, Identifiers & Profiles page of the Apple development site.

Where the push notifications option is entered, and you select Create certificate in its subkey development SSL certificate (because the certificate is for debugging purposes, it is created in development, There is also a distribution under the certificate, this will be released when the time to create, here we can ignore).

One step later requires uploading a CER certificate file, and we need to create a certificate locally.

The steps are: to open the Certificate Assistant in the Keychain Access program in the system, request certificate from the certification Authority option:

Next, store it on disk:

Then upload this generated certificate file to the Apple development website, and a new certificate will be generated, we will download it locally and double-click to import it into the keychain.

Open Keychain Access and locate the certificate you just imported, with the name similar to "Apple development IOS Push Services: Name of your App id", and you may find that there is a small line of red characters on it: information that the issuer of this certificate is invalid.

The workaround is simple:
0. First update the WWDR system certificate, go to Https://developer.apple.com/certificationauthority/AppleWWDRCA.cer to download the CER to local, double click the import keychain.
1. In the keychain, select login, then click on the certificate, in this interface, select the toolbar display and display expired certificate, this time you will find an expired Apple worldwide Developer relations certification Author ity, delete it
2. There is also this expired Apple worldwide Developer relations Certification authority in the System column, as well as deleting it
3. Now look at the status of the issuer, you can see the green "This certificate valid" Word:

Workaround for this certificate issuer is not valid after iOS registers a remote push message certificate