Delete a Missing Case
It's weird to see a case without a client. Maybe, it was created correctly and somehow civicrm_case_contact table row was deleted for this contact_id?

If you wish to delete this case from your site, you can make use of the API explorer - http://site-name/civicrm/api#explorer OR can be navigated through Support -&gt; Developer -&gt; API Explorer

Use Case Entity with Delete action and pass the case id as a parameter -



If you don't know the case id - you can check by placing your cursor on the subject column of the case detail report. The URL will be shown on the bottom left of your browser which has the caseId param as shown in the screenshot -