When attempting to open the CAB workbench calendar (/cab?id=cab_calendar) the calendar fails to load but only intermittently.
It's a node specific issue where one node has not gotten all the needed resources to load the calendar properly.
Restart the affected node(s).
1) Identify the node the user is currently logged in by either typing in stats.do in the filter navigator or in the URL directly (i.e. instancename.service-now.com/stats.do)
The node number can be found on the second line of the page where it says:
Connected to cluster node: app00000.sjc000.service-now.com:instance_name[node_number]
2) Open an incident in HI with the affected node names/numbers to have a support engineer restarts the affected node(s)