Error in backtesting using this code: MarketData.GetBars

Hi,

I have this error during backtesting (version. 5.2.11.39935) : 

Error | Failed to get symbol 'EURGBP': Symbol not found or has no quotes.

Info | Not Done with : EURGBP Renko20    at Robots.Test.OnStart() in .cs:line 211 Object reference not set to an instance of an object.

Here is my code:

foreach (var lTimeFrame in mTimeFrames.Keys)
{
	foreach (string lSymbol in mSymbolFrom)
	{
		Bars lBars = MarketData.GetBars(lTimeFrame, lSymbol); //This line cause the error, cause lbars => null after this initialisation
    }
}

FxPro is the broker.

Can you correct this bug ?

Best regards Frank