This issue was originally opened off the stash-build-plugin but after further investigation we found that the cron system of core jenkins stop working as expected.
Approximately weekly as of now with the introduction of more cron based plugins like stash-pullrequest-builder; the cron system stops working. With jenkins_debug_10072015.tar attachment; the system indicated for most jobs a last time polling of around 9:05-9:10am. All polling cron type jobs no longer responded.
Very close to JENKINS-25704; almost a duplicate.