After sorting out some Plugin issues, JIRA was working after the upgrade. It's suddenly stopped now with following error in logs:
2016-08-30 09:12:12,057 JIRA-Bootstrap ERROR [c.atlassian.jira.ComponentManager] Error occurred while starting component 'com.atlassian.jira.service.DefaultServiceManager'.
java.lang.IllegalArgumentException: Unsupported schedule type: I
at com.atlassian.jira.scheduler.ClusteredJobFactory.badType(ClusteredJobFactory.java:131)
at com.atlassian.jira.scheduler.ClusteredJobFactory.toScheduleType(ClusteredJobFactory.java:111)
at com.atlassian.jira.scheduler.ClusteredJobFactory.getSchedule(ClusteredJobFactory.java:70)
at com.atlassian.jira.scheduler.ClusteredJobFactory.build(ClusteredJobFactory.java:42)
at com.atlassian.jira.scheduler.ClusteredJobFactory.build(ClusteredJobFactory.java:21)
at com.atlassian.jira.entity.SelectQueryImpl$ExecutionContextImpl.forEach(SelectQueryImpl.java:231)
at com.atlassian.jira.entity.SelectQueryImpl$ExecutionContextImpl.consumeWith(SelectQueryImpl.java:214)
at com.atlassian.jira.entity.SelectQueryImpl$ExecutionContextImpl.singleValue(SelectQueryImpl.java:191)
at com.atlassian.jira.scheduler.OfBizClusteredJobDao.find(OfBizClusteredJobDao.java:88)
at com.atlassian.scheduler.caesium.impl.CaesiumSchedulerService.getJobDetails(CaesiumSchedulerService.java:230)
at com.atlassian.scheduler.core.DelegatingSchedulerService.getJobDetails(DelegatingSchedulerService.java:97)
at com.atlassian.jira.service.DefaultServiceManager.ensureServiceScheduled(DefaultServiceManager.java:538)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at com.atlassian.jira.service.DefaultServiceManager.ensureServicesScheduled(DefaultServiceManager.java:531)
at com.atlassian.jira.service.DefaultServiceManager.start(DefaultServiceManager.java:112)
at com.atlassian.jira.ComponentManager.runStartable(ComponentManager.java:280)
at com.atlassian.jira.ComponentManager.quickStart(ComponentManager.java:210)
at com.atlassian.jira.ComponentManager.start(ComponentManager.java:157)
at com.atlassian.jira.upgrade.PluginSystemLauncher.start(PluginSystemLauncher.java:43)
at com.atlassian.jira.startup.DefaultJiraLauncher.lambda$postDbLaunch$2(DefaultJiraLauncher.java:144)
at com.atlassian.jira.config.database.DatabaseConfigurationManagerImpl.doNowOrEnqueue(DatabaseConfigurationManagerImpl.java:298)
at com.atlassian.jira.config.database.DatabaseConfigurationManagerImpl.doNowOrWhenDatabaseActivated(DatabaseConfigurationManagerImpl.java:194)
at com.atlassian.jira.startup.DefaultJiraLauncher.postDbLaunch(DefaultJiraLauncher.java:135)
at com.atlassian.jira.startup.DefaultJiraLauncher.lambda$start$0(DefaultJiraLauncher.java:101)
at com.atlassian.jira.util.devspeed.JiraDevSpeedTimer.run(JiraDevSpeedTimer.java:31)
at com.atlassian.jira.startup.DefaultJiraLauncher.start(DefaultJiraLauncher.java:99)
at com.atlassian.jira.startup.LauncherContextListener.initSlowStuff(LauncherContextListener.java:149)
at java.lang.Thread.run(Thread.java:745)
I can't find anything referencing this on the web so am now at a loss as to a fix. Java version is correct. Plugins are fine. Get the same issue when all plugins removed.
JIRA runs but is locked with redirect to "JIRALockedError" page. Ubuntu installation.