Once issues have been created, modifying the configuration of your JIRA instance can result in the search index becoming out-of-sync with JIRA's configuration. Configuration details such as the following can affect the search index:

If you make changes to any of these areas of configuration, you might see the following message in your Administration view:

USERFULLNAME made configuration changes to 'SECTION' at TIME. It is recommended that you perform a re-index. It is recommended that you perform a re-index. For more information, please click the Help icon.
To perform the re-index now, please go to the 'Indexing' section.
Note: So that you only have to re-index once, you may wish to  complete any other configuration changes before performing the re-index.

All users that have access to the Administration Tab will see this message (JIRA Administrators, System Administrators, Project Administrators). The above message means that configuration changes have been made to JIRA, but have not yet been reflected in the search index. Until JIRA's search index has been rebuilt, it is possible that some search queries from JIRA will return incorrect results. For example:

The way to resolve the discrepancy is to rebuild JIRA's search index . This can take anywhere from seconds to hours, depending on the number of issues and comments in your JIRA instance. While re-indexing is taking place, your instance will be unavailable to all users unless you chose Background Indexing. For these reasons, it is recommended that you: