If a customer has set the regional settings incorrectly (i.e. any non-US standard setting), NPC will error out when navigating through various time periods with the error:
"String was not recognized as a valid DateTime"
This error can be caused by various invalid dates in the data due to the regional settings being incorrect.
Note: This will only resolve the date format in new data. Old data will not be updated, so you will still see errors when looking at older data from before the changes.
Set the regional settings to US where it is M/D/Y instead of D/M/Y.