I am trying to run virtualbox inside a docker container, on macOS. So far I can install virtualbox and setup a VM, but I cannot run it because the vboxdrv kernel module is not loaded.

In opposition to Docker toolbox, Docker for Windows and Docker for Mac are designed to give you the feeling that Docker is running directly on your OS, so they use lightweight virtual machines running under lightweight hypervisors (instead of VirtualBox) handled directly by the docker executable. Hence you won't see them with docker-machine and you won't see another IP address than localhost.

Why playing video games is healthy. I could make it work in a Debian distribution installing the required headers ( sudo apt-get install linux-headers-generic virtualbox-dkms) but I have no idea on how to solve this issue on MacOS.

Co-worker sends me an xlsx created with Excel for Windows from Office 365 subscription. I edit it with Excel for Mac 16.20 (181208) and save it in SharePoint Sites or OneDrive for Business. Reopening it with Excel for Mac or Excel Online pops up the alert.