Application links over https only working one way

[Callum Carlile _Automation Consultants_]

I have configured Jira Service Desk and Confluence over SSL. These both work successfully, and there are no problems with the certificates. The certificates come from an internal CA.

I had set up the application links between the two before I configured the SSL and they worked fine, but now they are not.

When I create the link from Confluence to Service Desk, the link works, however when I am redirected to Service Desk to create the reciprocated link I get the warning 'It has not been possible to retrieve the required information from https://<myconfluenceURL>'.

I have followed the exact same steps to add the certificates to the cacerts trust store in the Java folders of each of the applications, and have checked that the certificates have been added to this trust store successfully, and they have. But for some reason, Service Desk does not trust confluence.

I have followed the troubleshooting guide (https://confluence.atlassian.com/kb/ssl-and-application-link-troubleshooting-guide-719095282.html\) but can not find the solution.

The error in the logs reads:

javax.net.ssl.SSLHandshakeException
sun.security.validator.ValidatorException: PKIX path building failed:
sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Does anyone have any suggestions?