So I’ve just finished rolling out a fresh UCCX 12.5.x cluster. One of the interesting issues I came across during the build was the “Enable Queue Stats” setting. After enabling queue stats (appadmin > cisco unified cm telephony > advanced settings > queue stats) and a subsequent reboot, I could no longer call into any of the triggers.

When doing a reactive debug within CCX Editor I would get the following error:
Contact ID:x, Channel ID:y, Contact is in Terminated/Connected state.
Since I had only enabled the queue stats setting, I rolled back the change and then rebooted the servers. I figured that ‘enable queue stats’ was required for reporting but it is not.
I could not find on Cisco’s website, anything that explained what the setting actually did. So after logging with Cisco TAC:

Enable Queue Stats – Causes JTAPI to log the max queue depth over the specified number of messages that are queued to JTAP main event thread. For every X message processed, JTAPI logs a DEBUGGING level trace that reports the maximum queue depth over that interval, where x represents the number of messages that are specific in Queue Size Threshold.
Queue Size Threshold – Specifies the number of messages that define the interval over which JTAPI will report the maximum queue depth.

So turns out the Queue Stats setting within the UCCX advanced settings is for advanced tuning of JTAPI and not for any type of reporting.
Note this was on version Resolution was just to turn off “Enable Queue Stats” and reboot the HA cluster in sequence. The errors related to codec mismatch when pulling the debugs from RTMT.
I hope this helps anyone else who comes across this issue.