ESRS-IP SSL issue

Hello,

I'm having trouble with ESRS - IP , the software was working fine , but something happened .

He started giving the following error in diagnostic:

Server error (Error indicates a problem in communication with the server.):

SSL: server certificate issuer unknown (Issuer of the server certificate is not trusted. Add server CA certificate to the CA certificate file.)

Enterprise server: https://esrs-core.emc.com/eMessage

Can someone help me?