Re #8602. Added a few print-outs for debugging.
Re #8602. Cancel MonitorLiveData when if background thread stops
Re #8602. Removed print-outs.
Re #8602. Corrected spectra-detector mapping.
Re #8602. Fixed a mistake.
Re #8602. Fixed a memory leak.
Merge remote-tracking branch 'origin/bugfix/8602_let_events_fail'