Workflow timers stuck
Scheduler not processing jobs in the instance
sys_trigger table has lots of jobs queued in Red ready state
The Cluster Control [sys_cluster_control] paused flag was set to true
Basic trouble shooting:
1) Restart (Stop and Start) the schedulers from the Left Navigator (Type scheduler in the left navigator) and check the status.
2) The other issue could be upgrade pause did not change its status.
Go to [sys_cluster_control] table and set the Pause flag to false