In the Symbol Settings you can configure the copier status for a specific symbol it will define if the copy trading is currently active or not, you can choose to copy all trades, or copy only trades that open (Open Only) or close a position (Close Only), or to deactivate the copy (OFF). In such case you could receive a Deleted: Symbol is FROZEN/OpenOnly/CloseOnly Mode order status, if your master try to place an order on such symbol on which you have defined a specific configuration.
Learn more on Symbol Settings here.