This was tested on a Mac Pro 5,1 running 10.10.5 with VirtualBox 5.0.14. Starting up the machine after this change will then present a serial number that matches the base system and applications will function correctly.

Make sure you remove the quotes while entering the above command. In Terminal run the following command substituting the name of your VirtualBox virtual machine and your serial number (all one line): VBoxManage setextradata “” VBoxInternal/Devices/efi/0/Config/DmiSystemSerial ““ Pro: Oracle VM VirtualBox is a free, open-source virtualization software product that can create emulated machines on Windows, Linux, Mac OS X and Oracle. On my Mac Pro 5,1 it begins with a letter and is 11 characters long. The solution is to determine the serial number of the real Mac by opening About This Mac or running System Information. But due to the serial number being “0” the App Store and Server applications will not work. Of course OS X runs just fine inside VirtualBox running on a Mac even in that case. VirtualBox does not by default make a serial number available to OS X guests. Then below solution will definitely fix your problem.

Check the serial number in about us in VM.