Warning: Attempt to read property “post_type” on null in

Hello, I’m sorry to hear that you’re experiencing this issue with the Repair Action Scheduler plugin. It seems like the repair database schema is obsolete and the plugin couldn’t run as expected.

In this case, I recommend trying the alternative method provided in our knowledge base article for advanced users. You can install a code snippet to address the issue. Here are the steps:

1. Head over to the Snippets menu in the left sidebar and click Add New.
   

2. Give that post any name and copy the below code in the Code field:
   add_action( 'init', function() { delete_option( 'schema-ActionScheduler_StoreSchema' ); } );

3. Select ‘Only run in administration area’ option and click the Save Changes and Activate button.
   

4. Open WordPress Dashboard in a new window.

5. Then deactivate the recently created snippet from here.
   

6. Finally, activate the Rank Math plugin again.

Please ensure to clear all the cache, including the server, after following these steps. This should help resolve the issue you’re facing.

If you have any further questions or need additional assistance, please feel free to reach out.

Sources:
Fatal Error Happening on Some Installations After 1.0.49 Update » Rank Math
How to Fix ‘Action Scheduler: 0 past-due actions found; something may be wrong’ » Rank Math