Not sure if yours is deleted or expired. Can't seem to find anything on a certificate that's deleted. but here's what whatsapp says about an expireds certificate on Nokia devices:
I get a "Certificate Expired" error message. What does this mean?
The "Certificate Expired" message can mean any of the following:
The date, time and/or year in your device are incorrect.
You need to update your device software to the latest available.
For information on how to update your device software with Nokia, please visit Nokia's website: http://www.nokia.com/global/support/locations/
If you are using a Sony Ericsson Vivaz phone and you are still having the problems after checking the above, unfortunately this is a known issue and there is nothing we can do to help at this moment.