I've updated one of our Jiras to Jira 6. Prior to the upgrade we had application links between 2 Jiras that was working fine. After the upgrade, attempting to create a link from the Jira6 to the Jira5 instance fails. But we can create the link (and a reciprocal link) staring from the Jira5 instance.
I've got both Trusted and OAuth access setup on both sides.
When I try to create the link I receive the message:
Unable to create a link to LabOps JIRA as the application does not have any authentication configured.