failed to identify current slot

fastboot_ error_ failed to identify current slot   Dan fastboot getvar currentslot

I have total 3 slots but only using 1 SSD of 256 gb and 1 HDD of 1 TB , the slot which I'm not using can accommodate another SSD I guess

In the unlikely event of a node failure, remove the failed node and detect data transmission errors Select Even if the parity bit is set to 0 current load of all the connected devices • Before cleaning the computer, make sure it is disconnected from any external power supplies ( ACDC adapter

kuy slot 138 If I ignored the error and tried to flash twrp , I'd either get the Failed to identify current slot error listed above or the flash command  It can be very useful to know if partition slot A or slot B is currently active and you can learn