Error trap added

src/engine/gameManager/MaintenanceManager.java

@@ -45,10 +45,13 @@ public enum MaintenanceManager {
         // Deduct upkeep and build list of buildings
         // which did not have funds available
 
+        try {
             for (Building building : maintList)
                 if (chargeUpkeep(building) == false)
                     derankList.add(building);
-
+        } catch (Exception e) {
+            Logger.error(e);
+        }
         // Reset maintenance dates for these buildings
 
         for (Building building : maintList)