Unable to connect to SSL services due to "PKIX Path Building Failed" error

[BANGUE]

Unable to connect to SSL services due to "PKIX Path Building Failed" error.

Can you help me please

[Nic Brough -Adaptavist-]

This is usually down to a missing certificate somewhere.  Usually on the server side, when one server (with incorrect or missing certificate(s) ) is missing

Have a run through https://confluence.atlassian.com/kb/ssl-and-application-link-troubleshooting-guide-719095282.html - that usually helps us find a missing or broken certificate.

[Tova Pozen]

I'm trying to call one of Confluence OOB REST APIs from within a Confluence java plugin, and the call is failing with this error.

It makes sense, since our Confluence is running over SSL. But what is the solution? Do I have to import Confluence SSL certificate in its own trust-store?