Fern freezes after selecting Wifi card about fern-wifi-cracker HOT 5 OPEN

Depending on your operating system, it sometimes take a while to place the card 
into monitor mode, wait for the monitor setting process to complete, when done 
the Interface will display a message that the card in now monitor mode 
activated.

I got exactly the same problem. I know the steps may take a while, but several 
minutes totally frozen with no disk activity? The famous "capslock led test" 
also failed (even the capslock led is frozen).

I don't know why or how, in the universe of the possibilities, I have found the 
solution:

* Run this: airmon-ng start wlan0
* Put the wireless switch off
* Select the wlan0 as interface in Fern
* Put the wireless switch on
* Wait a few seconds
* Start scanning

I hope this may help.

Thanks ;)

Still freezes for me once I put the wireless switch back on :(