Which type of device are you using? Is your power voltage 220v? The device only supports 2.4G network instead of 5G.
Also, please check if the device is present in your router’s DHCP list.
i get this error lots of times. from collection of >10 bulbs. what i later discovered - after seeing that error message, i simply quit the process (stuck at 99%) and attempt to “find new device” again, then you will see that the new bulb is already connected. so actually need not reset. it seems it’s been setup/connected correctly just that status is stuck at 99% then the false-positive error message.