How to upgrade Jira core from 8.2.1 to the latest version?

[Mark Gesite]

When attempting to upgrade, it says: "Required - current version is incompatible with Jira Core 8.8.0" I can't find online which version to upgrade first before going to the latest version. Should I go with 8.3 to 8.4 until i reach 8.8? Also, do I need to do the same with Jira Service Desk? Thanks

[Mike Sorensen]

I would do this in a script set to "validate" the record on creation. 

If the Reporter is specific user "2" then Assignee is specific user "1"

[Matthias Catherine]

Hello Mike, Thanks for the answer. I'm using the Cloud version of Jira (No Script Runner), do you know how i can implement scripts ? Thx

[Mike Sorensen]

How about a transition that validates if Assignee is user 2, is set to run automatically, and has a post function of assigning to user 1. Automatic running of transitions is something I've done regularly but not with cloud version and I had to be administrator to start it because I had to edit the XML version of the workflows.