fix issue in invoices tab

cmsWebApp/src/performa/utils/StripeUtils.java

@@ -13,6 +13,7 @@ import com.stripe.model.Invoice;
 import com.stripe.model.Plan;
 import com.stripe.model.Subscription;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.HashMap;
@@ -125,6 +126,8 @@ public class StripeUtils
     
     public static List<Invoice> retrieveInvoices(Company company) throws FieldException
     {
+        if(company.getStripeSubscription() != null)
+        {
             try 
             {
                 Map<String, Object> invoiceParams = new HashMap<>();
@@ -137,8 +140,9 @@ public class StripeUtils
             {
                 LogMgr.log(LoggingArea.ALL, LogLevel.PROCESSING1, ex, "Error while retriving invoices in stripe for subscription: " + company.getStripeSubscription());
             } 
+        }
         
-        return null;
+        return new ArrayList<>();
     }