From Splunk Wiki
Are you having performance issues or problems when navigating between apps or Manager pages in the Splunk UI? If your server doesn't have an internet connection, this may be your problem -
The Splunk UI occasionally checks with splunk.com for new versions and other resources. If your Splunk host does not have access to the Internet, these will fail. Occasionally this causes the UI to hang waiting to timeout attempting to reach a resource that will never be available.
For the Launcher app, change the remote_tab setting to disable checking for new apps. In
$SPLUNK_HOME/etc/apps/launcher/local/app.conf (create if necessary) add the following stanza:
[launcher] remote_tab = false
To disable checking for new versions, add updateCheckerBaseURL to web.conf:
[settings] updateCheckerBaseURL = 0
- Note: set this to updateCheckerBaseURL = NONE if you are using version 4.04 or an older version of Splunk.
After changing these conf files, you need to restart Splunk.