Completed the upgrade (from 7.3.3 to 8.4.2), using the installer, on Windows. After attempting to start it the first time, it said the license was out of date and requested that I provide a valid license. I supplied it with the valid license from my.atlassian.com/product. It then returned this error message.
Technical details
Log's referral number: d98cda2e-82f1-476a-b7a7-3771a8657a7e
Cause
Referer URL: http://localhost:8089/secure/ConfirmNewInstallationWithOldLicense!default.jspa
java.lang.IllegalStateException: setLicense called with illegal ValidationResult object
these are the first few lines of the illegalstateexception... its a few hundred lines long.
java.lang.IllegalStateException: setLicense called with illegal ValidationResult object
at com.atlassian.jira.bc.license.JiraLicenseServiceImpl.setLicense(JiraLicenseServiceImpl.java:172) [classes/:?]
at com.atlassian.jira.web.action.admin.ConfirmNewInstallationWithOldLicense.executeNewLicense(ConfirmNewInstallationWithOldLicense.java:303) [classes/:?]
at com.atlassian.jira.web.action.admin.ConfirmNewInstallationWithOldLicense.doExecute(ConfirmNewInstallationWithOldLicense.java:254) [classes/:?]
at webwork.action.ActionSupport.execute(ActionSupport.java:165) [webwork-1.4-atlassian-30.jar:?]
at com.atlassian.jira.action.JiraActionSupport.execute(JiraActionSupport.java:63) [jira-api-8.4.2.jar:?]