How to downgrade Service Desk application

[Deleted user]

I installed by error a new version of Service Desk. How can I retrieve the previous version? If Service Desk was a plugin it would be simple: uninstall it on the UPM and then install previous version.

I tried to go to application section, uninstall Service Desk, then upload the previous version ZIP downloaded from Atlassian. It didn't work. Service Desk kept uninstalled. Don't know why. As ever, JIRA's frequent errors and incorrect behaviours are a mystery.

[Nic Brough -Adaptavist-]

As usual, I'd expect the log file to tell you why the re-install from upload has not worked.  What does that say when you try the upload?