Symptoms

The following error message appears in the JIRA UI when clicking on 'All' or 'Transitions' issue tab panel:

An unknown error occurred - actions == null. Please see logs for more details.

When reviewing the logs, the following error can be found in the logs:

...
Caused by: java.lang.NoClassDefFoundError: edu/emory/mathcs/backport/java/util/Collections
at com.googlecode.jsu.transitionssummary.issuetabpanel.TransitionsSummaryTabPanel.getActions(TransitionsSummaryTabPanel.java:48)
at com.atlassian.jira.issue.tabpanels.AllTabPanel.getActions(AllTabPanel.java:44)
...

Cause

This problem is caused by the third-party plugin called JIRA Suite Utilities. The error occurs because the JIRA instance is running with an old version of the plugin that is not compatible with the version below JIRA that is being used.

Resolution

Remove the old plugin version of the plugin and replace it with a version that is compatible with your version of JIRA. For compatibility charts and installation directions, refer to the JIRA Suite Utilities page.