They are under no obligation to produce new batteries for their old products. Try to get a security update for Windows 95. Or a new engine for Corolla 200x. None available.
Best we can do is to snatch NOS batteries off ebaywhen someone closes a hobby store. Or gobble them up when DJI is dumping...
Better invest into a dedicated USB simulator controller. The Phantom controller was not intended for simulators use. The reason its recognized by USB is for controller's firmware upgrades, not for it to be used as input device.
This message can pop-up when cells' voltage is outside normal spreas. Dont throw the battery away, but try to charge/discharge it few times on the ground, i.e. let the drone spin props without taking off. Then check voltages again.