Same boat here. Both VMware and VirtualBox installed. Both worked fine before macOS Sierra. After updated to Sierra, I get the same error message trying to open a VMware VM. Uninstalling VirtualBox and re-installing VMware fixed the issue but ultimately I need VirtualBox as well for various things.
Edit: tried to re-install VirtualBox after I got everything working again with VMware 7.1.3, and it seems VirtualBox will not install in macOS Sierra. So maybe this is more related to VirtualBox than VMware(?):