I Stand Up For Myself

I'm using Ubuntu 16.04. My wifi worked just as normal two days ago, but today it was suddently broken. Normally, there should be an "enable wifi" option on the top panel bar, but I couldn't see it today.

I typed:

nmcli dev

but I couldn't see any device that's related to wifi.

DEVICE   TYPE      STATE
enp5s0   ethernet  unavailable
lo       loopback  unmanaged

Therefore, I spent 3 hours searching for lots of forums, but still couldn't solve the problem. This is all the websites I had viewed during that 3 hours:

http://www.wallcopper.com/linux/2596.html
https://unix.stackexchange.com/questions/234452/nmcli-device-eth1-unavailable
https://www.linuxquestions.org/questions/linux-networking-3/nmcli-device-eth1-unavailable-4175555503/
https://bbs.archlinux.org/viewtopic.php?id=231991
https://wiki.archlinux.org/index.php/Network_configuration#Device_names
https://stackoverflow.com/questions/45691434/nmcli-device-unavailable
https://askubuntu.com/questions/855240/ubuntu-16-04-how-to-re-enable-wifi
https://askubuntu.com/questions/946235/unable-to-activate-enable-wireless
https://askubuntu.com/questions/71159/network-manager-says-device-not-managed
https://nullr0ute.com/2016/09/connect-to-a-wireless-network-using-command-line-nmcli/
https://askubuntu.com/questions/900568/connection-could-not-be-found
https://fedoraproject.org/wiki/Networking/CLI
https://unix.stackexchange.com/questions/236514/how-do-i-attach-devices-to-connections-using-nmcli
https://unix.stackexchange.com/questions/158328/network-manager-not-listing-wifi
https://askubuntu.com/questions/715345/network-manager-is-not-detecting-wifi-networks/921392#921392
https://ask.fedoraproject.org/en/question/64217/how-to-connect-to-wifi-using-nmcli/
https://ubuntuforums.org/showthread.php?t=2354066&page=5
https://ubuntuforums.org/showthread.php?t=2214911
https://ubuntuforums.org/showthread.php?t=1195312
https://ubuntuforums.org/showthread.php?t=1314693
https://ubuntuforums.org/showthread.php?t=2381037
https://askubuntu.com/questions/858546/wifi-not-working-intel-on-hp-spectre-x360-13/859263#859263
https://ubuntuforums.org/showthread.php?t=2356217
https://askubuntu.com/questions/996178/network-unclaimed-ubuntu-16-04?rq=1
https://superuser.com/questions/1288879/ubuntu-16-04-cannot-detect-wifi
https://medium.com/@lgobinath/no-ethernet-connection-in-ubuntu-16-04-linux-mint-18-with-realtek-rtl8111-8168-8411-7ae2779dc9b8
https://unix.stackexchange.com/questions/417262/network-unclaimed-ubuntu-16-04
https://answers.launchpad.net/ubuntu/+source/gnome-nettool/+question/657341

I was exhausted and frustrated, because I couldn't do what I had planned to do tonight and I also couldn't fix my wifi. Fortunately, I read a line in the last link above, that I could reboot and choose a previous kernel version. I remember that I was in 4.15.0-33 a few days ago, but now I was in 4.15.0-34 instead. After I changed to the previous version, my wifi just started working.....

WTF IS KERNEL 4.15.0-34 DOING?? I've spent 3 hours worthlessly just dealing with that stupid update! I mean, this is such a meaningless thing to do, for one spending lots of time just to figure out there's a kernel update that's not compatible with a particular driver. Shouldn't this be the responsibility of the dev? 

This lesson teaches us: When there's a weird problem on Linux, always try to roll back to a previous kernel version.