Report failing when running.

Hello,
A client has an issue when she runs her daily report using the Eikon API. The report is returning no RICs as it used to in the past, here's the line of code that is failing:

private void CreateRDataBtn_Click(string argument,string dateStart,string dateEnd,EventArgs e)

{

string instrument="";

string[] data=argument.Split('.');

if(data[1]=="TO")

{

data[1]="XTSE";

}

else

{

data[1] = "XNYS";

}

if (data[0]== "Hi")

{

instrument = "SCREEN(U(IN(Equity(active,public,primary,countryprimaryquote))),IN(TR.ExchangeMarketIdCode,'" + data[1] + "'),BETWEEN(TR.Price52WeekHighDate," + dateEnd + "," + dateEnd + "))";

}

else

{

instrument = "SCREEN(U(IN(Equity(active,public,primary,countryprimaryquote))),IN(TR.ExchangeMarketIdCode,'" + data[1] + "'),BETWEEN(TR.Price52WeekLowDate," + dateEnd + "," + dateEnd + "))";

}

Can you please tell me what is wrong or suggest improvement?
Please let me know if you need any further information.
Thank you,
Max