Universal Plugin Manager 3.0.10 breaks Jira

[user1647473884182]

Just had to roll back the latest upgrade of the Universal Upgrade Manager (UPM) after it broke Jira. Most of our Add-Ons disappeared including Jira itself because of a new dependency introduced by the new version of UPM.
If you get caught out and are on Data Center, to fix it:

- download the previous version (3.0.6) from here https://marketplace.atlassian.com/apps/23915/atlassian-universal-plugin-manager/version-history 
- copy to your "Shared home" here: ...\shared-j\plugins\installed-plugins
- rename the existing jar file for the new version so it does not have a ".jar" extension. The file will be named something like this "plugin.603000996800941594.atlassian-universal-plugin-manager-plugin-3.0.10.jar".
- rename the jar file for the older version to have the same name (except the version of course), e.g. plugin.603000996800941594.atlassian-universal-plugin-manager-plugin-3.0.6.jar
- then take each node out of your cluster one by one restarting them and replacing them in the cluster.

[user1647473884182]

Catch-22 response from Atlassian Support with whom I raised a ticket about this:

Paraphrase: You are using a version of Jira we no longer support. We recommend you first upgrade Jira then come back to us when you have upgraded.

So we are currently in the process of upgrading. This includes making sure all our Add-Ons are up to date. Atlassian Add-On management page recommended we upgraded their Add-On Universal Upgrade Manager plugin to a version which breaks our version of Jira including the Add-On management (which disappeared as a result of upgrading it).  When I asked for support, they said go away until you have upgraded Jira (See above), but to upgrade Jira I need to upgrade our Add-Ons which will break Jira. Alternatively, I could ignore recommendations from Atlassian to upgrade Add-Ons thus risking the Jira upgrade which is their only recommendation for the current problem. So either I follow their recommendation and install the Add-On upgrade and break Jira or I follow their recommendation to upgrade Jira and break (potentially) the upgrade!

By the way, on their online bug report, our version of Jira (7.6.10) was missing from their drop down of versions which includes much earlier versions.