SSL from another provider - installation

[JohnyByk]

I have a problem with the installation certificate supplied by the client. The client sent to us a private key, CSR and certificate. I added the private key and certificate in DA panel, but the certificate does not work properly. Browser shows a warnings.
How to install the certificate provided entirely "outside"? Client generated the CSR from another provider?

Our certificates (CSR generated on our server) are working properly.

How to install SSL certificates from another providers?

Regards

 

[Petertjuh360]

Check for a CA Root certificate.

 

[JohnyByk]

Root CA certificate should be provided by the customer?
How do I install it?
In Certificate Authority SSL Certificate section (DA Panel)?

Thank for help
Regards

 

[zEitEr]

You can download them from a site of a company that issued the SSL cert. They are public.