Jira - FishEye linking issue

We run Jira 6.2.1 and FishEye/Crucible 3.3.1.

We cannot see the source tab for Jira issues.

I DID NOT ultimately follow the instructions here:
https://confluence.atlassian.com/display/FISHEYE/Configuring+authentication+for+an+application+link

Instead of "Trusted application links" that the above document suggests, I used OAuth authentication which I read elsewhere is required to see the new Development pane on the right-hand side. This panel now shows up.

After clicking OAuth two-way authentication on and off 3-4 times I finally got both sides, FishEye and Jira, to talk to each other.

The "Source" pane in "Activity" showed up.

Two issues that may or may not be related to this problem. First, when a colleague clicked on an item in the "Development" pane towards the bottom at the right, he was required to authenticate himself on the FishEye/Crucible server. This in spite of the fact that it is the Jira instance that handles usernames and passwords. This must clearly be a bug.

Secondly, 2-3 minutes later when I got back to my desk to triumphantly write an email to state that it worked, the "Source" pane was gone.

On the FishEye/Crucible server under "Application Links" in the first pane that comes up, every time it is opened, "Trusted application links", one could see one quarter of an error screen. This error screen requested that I give my credentials for loggin into the Jira server. I did so, but the source pane remains gone.