I'm new to Atlassian products. After a fresh server install of Jira 7.3.1, Confluence 6.1.4 and Bitbucket 5.0.1 on Ubuntu 16.04 I changed the access method for all three products to HTTPS/SSL and created bidirectional application links from Bitbucket to Jira and from Bitbucket to Confluence. Working well.
The existing application link between Jira and Confluence was broken due to the switch from HTTP to HTTPS/SSL. So I deleted this broken application link.
But I had no success creating this application link newly:
On the Jira form "Application Links" (<jira>/plugins/servlet/applinks/listApplicationLinks) I entered the Confluence Base URL.
The "Link applications" dialog was shown, where I checked "The servers have the same set of users and usernames".
The "Administrator Access" dialog was shown.
After logging in again the Jira form "Application Links" was shown without a newly created application link. There was no error message and no switch to Confluence to create the reciprocal application link.
In <jira>/logs/catalina.out I found the following entry:
<timestamp> JIRA-EventThread-73 WARN <user> 1330x2098x2 iucv0o 2.166.2.242 /rest/applinks/3.0/manifest.json [c.a.a.internal.capabilities.DefaultRemoteCapabilitiesService] Exception trying to get Applink for manifest with ID 065086d1-5d0c-3faf-a14b-520c62269424
(One note: I'm using two self signed certificates: one for Jira and Confluence and one for Bitbucket.)