I have an issue very similar to (Ubuntu 17.10 Drivers Not Found/Working Properly?), but this was done on a fresh install of Kubuntu 18.04. This desktop doesn't have an internal Wi-Fi card and I'm currently using an old wi-fi module to get an internet connection there. The main issue with the old wi-fi dongle is that it doesn't have the proper antenna to provide adequate wi-fi connectivity, as this desktop is in a remote location where ethernet cords cannot easily reach, and where wi-fi signals are faint at best.
I used the new wi-fi antenna, which is the source of the trouble, first, and folowed the steps layed out in (Ubuntu 17.10 Drivers Not Found/Working Properly?) to try and get it to work. It didn't.
I made sure to not have the old wi-fi antenna in the USB slot while I was following the commands and only re-inserted it after completing all command and restarting the system and realizing that the steps were unsuccessful in being able to restore the USB antenna-driver functionality.
The New USB Antenna is the exact same as the one listed in (Ubuntu 17.10 Drivers Not Found/Working Properly?)
Edit 0: sudo dkms status
yields
rtl8812au, 4.2.2: added
rtl8812AU, 5: added
**Edit **: Output of lsusb
(With Both USB Antennae in the USB ports)
Bus 002 Device 005: ID 0bda:8176 Realtek Semiconductor Corp. RTL8188CUS 802.11n WLAN Adapter
Bus 002 Device 002: ID 0bda:a811 Realtek Semiconductor Corp.
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 008 Device 003: ID 0461:4d22 Primax Electronics, Ltd
Bus 008 Device 002: ID 413c:2106 Dell Computer Corp. Dell QuietKey Keyboard
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Edit 1: Modprobe Info & Secure Boot
sarah@SciLabComp0:~$ sudo modprobe 8812au
modprobe: ERROR: could not insert '8812au': Exec format error
sarah@SciLabComp0:~$ modinfo 8812au | grep A811
alias: usb:v7392pA811d*dc*dsc*dp*ic*isc*ip*in*
Mokutil (The recommended way to check if secure boot is enabled based on another ask ubuntu question):
sarah@SciLabComp0:~$ mokutil --sb-state
EFI variables are not supported on this system
sudo dkms status
saysrtl8812au, 4.3.8.12175.20140902+dfsg, 4.15.0-22-generic, x86_64: installed rtl8812au, 4.3.8.12175.20140902+dfsg, 4.15.0-23-generic, x86_64: installed
– Sarah Szabo Jun 12 '18 at 18:03lsusb
with the antenna plugged in, of course. – chili555 Jun 12 '18 at 19:05lsusb
command, is that ok? – Sarah Szabo Jun 13 '18 at 01:15sudo modprobe 8812au
and also:modinfo 8812au | grep A811
??Secure Boot?? – chili555 Jun 13 '18 at 01:36