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- Manage Add-Ons: is the JSU Plugin add-on enabled... and all modules enabled (except one, which is disabled per default!)?
- Check your log files, serious problems usually leave a stacktrace. Do you see a reference to a class com.googlecode.jsu.*? (to determent which module cannot be loaded)
- Have you tried to remove JSU plugin add-on and reinstall it? (without restarting JIRA)
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