Fix disappearing WiFi card in VirtualBox or VMware
I'm using Panda and ALFA WiFi cards (Wireless Adapters) in a Linux (Ubuntu) virtual machine on a Windows 10 host a lot. When I started to use them, I had an issue where the cards would just seemingly randomly disappear. In my
dmesg logs, I would see messages like this:
Error - Vendor Request 0x07 failed for offset 0x1004 with error -71
It turns out that the underlying issue is power management on the Windows 10 host. To fix this and have a persistently available WiFi card for monitor mode, disable the option to allow Windows to turn off the device to save power. You can find the setting under "Devices and Printers" -> [your WiFi adapter] (note that it won't show up in the list if it is currently connected to your VM) -> Hardware -> Properties -> Change Settings -> Power Management.