How to import a SSL certificate signed by a CA?

Hi there

I have a certificate authority and I created a certificate for my freenas server.
When I try to import it, it says the private rsa or dsa key is not valid or not found.

When I try to import a private key & certificate with this format it says "RSA or DSA private key not found":
-----BEGIN PRIVATE KEY-----
[...] base64
-----END PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
[...]
-----END CERTIFICATE-----...

How to import a SSL certificate signed by a CA?