No accelerator found - failed to create HAX VM

Try to uninstall "Intel x86 Emulator Accelerator (HAXM installer)" from Android SDK manager, than install it again. That helped for me.

For those who installed Android Studio without HAXM built in. You need to install HAXM manually after you install it from sdk manager(actually the SDK manager just downloaded it).

Quote from here: https://software.intel.com/en-us/android/articles/installation-instructions-for-intel-hardware-accelerated-execution-manager-mac-os-x

The SDK Manager will download the installer to the "extras" directory, under the main SDK directory. Even though the SDK manager says "Installed" it actually means that the Intel HAXM executable was downloaded. You will still need to run the installer from the "extras" directory to finish installation.

So here is what you need to do:

• Download HAXM installer from SDK Manager->Android SDK->SDK Tools->HAXM installer

• Open <SDK_SRC>/extras/intel/Hardware_Accelerated_Execution_Manager/ and click the .dmg file to start install.

After installed manually, it's better to restart your PC.

Try installing or updating Intel Emulator Accelerator (HAXM installer) from SDK Manager and also check if Intel VT-x is enabled in your BIOS settings