The Calculator engine of a Node has as Next Wake Up value an abnormal value such as 11/06/1000 03:30:39.
This causes Cyclic tasks not being scheduled anymore and therefore not launching.
Most probably wrong Task definition
Release : 6.x
Component : Dollar Universe
Perform the following procedure:
1) From UVC, copy/ paste all the Enabled tasks to an excel
2) Then disable them all
3) Stop / Start Calculator Engine from Server Engine List so that Next Wake up date is updated
4) Then one by one enable again the tasks and check if the column Launch Date is populated
Do it until you find the task which is causing the problem. There is probably is a task causing the issue which needs to be fixed.