KVM is required to run this AVD

I am on Ubuntu 18.04 LTS and I am trying to set up Android Studio for the first time. When I run my simple "Hello World" app, it gives me a pop-up that says

KVM is required to run this AVD.
Unknown Error

Please file a bug against Android Studio

But when I run simply kvm-ok it outputs:

INFO: /dev/kvm exists
KVM acceleration can be used

Starting with Ubuntu 18.04 and Linux Mint Tara you need to install qemu-kvm

sudo apt install qemu-kvm

Check the ownership of /dev/kvm

ls -al /dev/kvm

Check which users are in the kvm group

grep kvm /etc/group

Output from the above command

kvm:x:some_number:

If there is nothing rightwards of the final :, there are no users in the kvm group.

To add the current user to the kvm group

sudo adduser $USER kvm

which adds the user to the group, and check once again with grep kvm /etc/group.

A restart may be required for the permissions to take effect.

Official answer on StackOverflow

Change sdk emulator folder permission. This is worked for me.

chmod 777 -R {sdk folder}/emulator

https://stackoverflow.com/questions/44635879/kvm-is-required-to-run-this-avd-unknown-error-please-file-a-bug-against-androi