BarsRequest error "The given key was not present in the dictionary."

[Bobin]

I get an error message "The given key was not present in the dictionary." when using BarsRequest.
The problem has only recently appeared.
I tried to delete the local database, delete the cache folder, restart Ninja Trader, restart my PC, but nothing worked. Still the same error message.
How do I fix the error?

I minimized the code to only print the error message. I call it in an indicator:

protected override void OnStateChange() {
    if (State == State.SetDefaults) {
      // ...
   } else if (State == State.Configure) {
      new BarsRequest(Instrument, DateTime.now.AddYears(-20), DateTime.now.AddYears(-1)) {
         MergePolicy = MergePolicy.MergeBackAdjusted,
         BarsPeriod = new BarsPeriod { BarsPeriodType = BarsPeriodType.Minute, Value = 1 },
         TradingHours = TradingHours,
      }.Request((bars, errorCode, errorMessage) => {
         if (errorCode != ErrorCode.NoError) {
            Print(string.Format("Error on requesting bars: {0}, {1}", errorCode, errorMessage));
            return;
         }
      });
   }
}

[Bobin]

I found a solution...
I replaced "TradingHours = TradingHours," with "TradingHours = Instrument.MasterInstrument.TradingHours," and now it works.
Very strange.

[NinjaTrader_ChelseaB]

Hello Bobin,

I'm uncertain on why the TradingHours would cause this error.

The working example I have posted on the link below, uses the TradingHours of the primary instrument without error.

https://ninjatrader.com/support/forum/forum/historical-beta-archive/version-8-beta/87988-barsrequest-question?p=1206656#post1206656

Is your script adding multiple series or something along these lines?
What TradingHours is selected for the primary series?