Hello,
I been having issues upgrading Jira. I do a back up, stop jira and run the latest installer (9.3.1) since we are running a lower version but once the installer finishes Jira will not come back up. I see the serves does not start and i think it might be a data base issue. We are using an H2 database. I get the screen shot attached. I also noticed in the installation step where i have to Reapply custom modifications to the following files ( jira-application.properties and WEB-INF/web.xml by Editing the new file, rather than copying the old files. Is this the reason why Jira is having problems with the upgrade ? I skipped that step.