We are using the LDAP-Plugin. We see the Login screen. Right after logging in, we only see a blank page (0 byte response). Before three days, it still worked fine. No idea if the addition of a new job suddenly overfilled the response header generation.

The /var/log/jenkins/jenkins.log shows:

Mar 18, 2016 4:10:39 PM org.eclipse.jetty.util.log.JavaUtilLog warn
WARNING: header full: java.lang.RuntimeException: Header>6144

When I reload the blank page, another "Header>6144"-message appears in the log.
The intervalled jobs still run in the background, but we are not able to see the GUI anymore.

When we set <useSecurity>false</useSecurity> in the config.xml and restart, it works fine. So it must have sth. to do with the security header cookies or header refreshes (page reloads).

Problem possibly related to:
JENKINS-25046
JENKINS-19946