When you disable connectivity with the Atlassian Marketplace, JIRA continues trying to reach the site to retrieve some data for the EOL Health Check.
Disable Marketplace connectivity
Remove the ability of the system to connect to marketplace
Check that jira-healthcheck-eol.json does not exist in JIRA_HOME
Restart the application (the health check will run in an interval, but this will trigger the error)
JIRA will respect the Marketplace setting and will not attempt to connect.
JIRA will attempt to connect and the following error is displayed in the logs:
Download the attached
and put it in your JIRA_HOME directory. If you are using JIRA Data Center, then place this file in the Shared home instead.