...
At IT KOBE we follow Atlassian End of Life policy. It means that our Marketplace Product will support all versions of Jira, Jira Core, Jira Software, Jira Service Management , and Confluence that have been released within the last two years. Earlier versions have reached End of Life and are unsupported.
...
Only unexpired licenses of the Marketplace Product are supported.
Only the most recent Marketplace Product version available on Atlassian Marketplace is supported. Please upgrade before contacting support.
The Marketplace Product version you are using must be compatible with the version of the Atlassian parent-product (Jira, Confluence, etc.) as indicated in the Marketplace listing.
The version of your Jira, Confluence, or other Atlassian parent-product of the Marketplace Product has not yet entered its Atlassian End of Life policy.