In addition: is it possible to use the entire Certificate Chain in Jive/PKI instead of only the server certificate:
AddTrust External CA Root
COMODO RSA Certification Authority
COMODO RSA Extended Validation Secure Server CA
Only Firefox users are receiving an error message? One thing to note is the SSL the certification should be placed on the Load Balancer: https://docs.jivesoftware.com/8.0_on_prem_int/sys_admin/jive.help.core/#admin/ConfiguringSSLonLoadBalancer.html
Yes it's only firefox users.
We do not have a load balancer , we only use the Proxy of Jive.
Ps, we also tried to add the ca to the cer file sourced by the httpd.ssl_certificate_file and httpd.ssl_certificate_key_file variable.
But that did not work as well , it seems Jive ignores everything past the ac certificate for the host.