Vagrant起動中に、Android Studioのエミュレーターを起動すると次のようにエラーとなりました。

/Users/[user]/Library/Android/sdk/tools/emulator -netdelay none -netspeed full -avd Nexus_9_API_22
Hax is enabled
Hax ram_size 0x60000000
HAX is working and emulator runs in fast virt mode.
emulator: Listening for console connections on port: 5554
Failed to sync vcpu reg
emulator: Serial number of this emulator (for ADB): emulator-5554
emulator: ERROR: Unfortunately, there's an incompatibility between HAXM hypervisor and VirtualBox 4.3.30+ which doesn't allow multiple hypervisors to co-exist.  It is being actively worked on; you can find out more about the issue at http://b.android.com/197915 (Android) and https://www.virtualbox.org/ticket/14294 (VirtualBox)
Failed to sync vcpu reg
Failed to sync vcpu reg
Internal error: initial hax sync failed