Thank you for your post and welcome to the forums!
There are a couple of things you can do.
Try to update your phone firmware using Firmware Over The Air, if your operator supports this.
Re-install the phone firmware using Nokia Suite / Nokia PC Suite. This should re-install the certificates as well.
If the problem still persists, visit your nearest Nokia Care Point.
Let us know if this helps,
Check the link given below for this.
My phone doesnot have certificate saw how i can get certificate for nokia 7210supernova please help
Did you check the link in the post above yours ...?