Your date and the format you are trying to parse it as do not match:
eg: date from javascript: "2016-09-05"
DateTime.ParseExact(dt, "dd/MM/yyyy",...
Try changing the format to "yyyy-MM-dd", and it should work.
But I'd strongly suggest using TryParseExact instead - it returns a boll success/fail code instead of throwing an exception when the format doesn't match.