Hey everyone,
thanks for your great work and continuing the project!
However we have a minor inconvenience at work because we use openSUSE 42.3 on our servers and are stuck with VirtualBox 5.1.32, so everytime we use it we get an error:

This version of phpVirtualBox (5.2-0) is incompatible with VirtualBox 5.1.32_SUSE. You probably need to download the latest phpVirtualBox 5.1-x.

Since there is no phpvirtualbox 5.1 there is no fix in sight.
For now I changed a line from

if(vers[0]+'.'+vers[1] != vStr) {

to

if(vers[0]+'.'+vers[1] == vStr) {

But maybe in the future you can include a checkbox that's setting a cookie warning-acknowledged: 1 or something like that.