ITBM when logging an incident getting an error message when saving:
"Item has already been added - key in dictionary '06/04/2007 00:00:00' Key being added '06/04/2007 00:00:00'
This indicates a duplicate bank holiday on one of the calendars for the date 06.04.07.
NOTE: this doesn't have to be the calendar for the response level you are selecting and could be stored in any calendar.
The workaround is to remove one of the duplicate bank holidays and reset IIS.
ITBM 7.1.1 onwards