Health check reports Application Link problem, but all links report connected

[greg_q10]

I just upgraded from 7.1.2 to 7.4.1.  JIRA has informed me that the Application Links health check failed.  It says:

One of your application links is reporting "Network error".

However, when I browse to the Application Links section, my two links look perfectly fine.  Both my Bitbucket and Bamboo links report "Connected" and there is no indication of a problem.

How can I fix the health check?

(https://community.atlassian.com/t5/JIRA-questions/Application-Health-fails-even-it-says-connected/qaq-p/610518 seems similar, but with no resolution)

[Suhas P]

Facing same issue with Fisheye. Most probably this is due to older version of Fisheye Application. Atlassian seems like encouraging customers to upgrade applications to latest versions. 

[Stefan Arnold]

Are there any entries in your logs about problems with application links?

[greg_q10]

The issue has mysteriously disappeared -- which, on one hand isn't too crazy, since there didn't appear to be anything wrong with them.  Still, it's odd that it presented itself in the first place.