You mean, now, as in after what ? I'm trying to understand what you have changed so that you get this error instead of the previous one. And you get it when? When you start Elasticsearch ? When you connect with a client ? What is this client ? a browser ? curl ? your java client ? what is the configuration of that client ?
The more precise you are in describing the behavior and errors you get, the easier will be for someone to help you 
please try by adding -v to curl and share the whole output, not just a line.
What do you "open" it with ? And by the client cert, do you mean client.p12 ?
I'm not sure I understand this. If you can't start Elasticsearch, how are you trying to connect to it as you said above ?
Please take the time to share the current setup in detail and also share at least :
- Your current elasticsearch.yml
- How ( with what tools and what commands exactly ) did you generate the certificates and keys you are using there.
- How exactly did you generate the client.p12
- Your exact curl command and the associated output