"CRITICAL ERROR: EventRouter is over capacity - events being rejected" in ThingWorx Platform

• Error encountered in EventProcessingSubsystem
• EventProcessingSubsystem queue size is over capacity
• Cannot open ThingWorx Composer 
• ThingWorx Platform instance down and CPU spiking to 100%
• Poor system performance preventing users from accessing application
• Tasks awaiting execution keeps up growing in EventProcessingSubsystem
• EventProcessingSubsystem is not able to keep up with the number of events being fired on ThingWorx
• Event Processing is falling behind after code change in ThingWorx Platform
• User experienced a situation where resources were being used excessively, is there a way to quickly identify which service is consuming ThingWorx resources 
• Completed Event tasks number is growing very slowly indicating the ThingWorx Platform is handling the request but in very poor performance
• System becomes unresponsive and user cannot login to the system until the system is restarted
• ThingWorx Platform takes a long period of time (possibly hours) to become accessible
• Event processing threads not completing in a timely manner
• Catchpoint Monitor - !DOWN! alert received for a PTC Cloud Hosted customer
• PTC Cloud Hosted instance was unavailable and exhibited the following alert
  

  • Catchpoint Monitor - !DOWN! : IoT/ThingWorx/<Customer Name>/<Namespace>/prd001

• Following error found in <ThingworxStorage>/logs/ApplicationLog.log

CRITICAL ERROR: EventRouter is over capacity - events being rejected Task com.thingworx.system.subsystems.eventprocessing.EventInstance@<ID> rejected from com.thingworx.common.utils.MonitoredThreadPoolExecutor@<ID>[Running, pool size = <Pool Size>, active threads = <Number of Threads>, queued tasks = <Number of Queued Tasks>, completed tasks = <Number of Completed Tasks>]

• Below error seen in ThingWorx Composer

Failed to return license click check

• The following error found in <ThingworxStorage>/logs/ApplicationLog.log file

[L: ERROR] [O: c.t.s.s.w.WSExecutionProcessingSubsystem] [I: ] [U: ???] [S: ] [P: ] [T: http-nio-8080-exec-51] CRITICAL ERROR: WSExecutionProcessor is over capacity - events being rejected