there is a way to install yunohost on top of debian thats for sure are going to help in that case, see the bottom of that thread:
there is a link with instructions how to do it,
so basically you can download debian and then install yunohost, debian will not produce such problem on virtualbox,
aside that make sure you’re using the latest virtualbox version with all the extensions installed, though i strongly advise you to use vmware due to many troubles you’re going to get in the future with virtualbox such as bloated disk,
hosting a server on a virtual machine is not the same as to host that on a physical one, there are many things need to come in concern, virtualbox is good for development and testing when you want to host a server that’s not the best choice though its free, its have many limitations and problems, but you can try,
in any case you decided to go farther with the virtualbox save this command for future use cause you will need it:
sudo dd if=/dev/zero of=wipefile bs=1024x1024; sudo rm wipefile
that will shrink your container (virtual hard disk) when it will be bloated after a while.
by the way the usual button “shrink disk” will not do anything but will say success when in reality your disk will stay at the same size" that’s why you need this command,
thee are other issues with networking and port mapping on virtualbox which are not always possible to solve but give it a shot.
also in your screenshot the “Extended Features: Enable 3D Acceleration” is unchecked, you need to check it for graphical use. though i am in doubt that’s the cause. but it should be checked anyway,
best regards