Is Virtualbox incompatible with Hyper-V in Windows 10?

VirtualBox 5.x cannot run if you are using HyperV virtual machines. Basically, both systems try to get exclusive access to the virtualization capabilities in the CPUs (e.g., the Intel VT-x extensions). HyperV, that runs below the Windows Operating System, gets the access first and impedes VirtualBox uses that capabilities.

You may check more information:

• Why VirtualBox or VMware can not run with Hyper-V enabled Windows 10
• Switch easily from VirtualBox to Hyper-V

UPDATE (10/03/2019): VirtualBox 6.0 has an experimental feature to work when Hyper-V is running. Basically, VirtualBox detects Hyper-V and executes the virtual machines using the Hyper-V capabilities.

• I had mixed experiences using VirtualBox 6.0 on Hyper-V: I had two computers where the VirtualBox works without problems, but another machine where the virtual machines froze after boot.