Jira Error - for loading dashboards and plugins

Today, i faced an issue with our Jira. I could login fine with my credentials. But when i tried to access the dashboard i am getting the following error

Fix:
    Stop JIRA.

    Make a backup of the following directory and all its subdirectories:

    $JIRA_HOME/caches/indexes

    Remove the following directory and all its subdirectories:

    $JIRA_HOME/caches/indexes

    This will be rebuilt when JIRA is next reindexed.

    Start JIRA.

    Perform a re-index of JIRA through the Administration section.