Solve virtual_hid_device_client not connected yet
problem
It seems there is some error around loading kext.
Could you execute the following command in Terminal app?
(The root password will be required in order to run kextutil command.)
1 | sudo kextutil -t '/Library/Application Support/org.pqrs/Karabiner-VirtualHIDDevice/Extensions/org.pqrs.driver.Karabiner.VirtualHIDDevice.v061000.kext' |