virtualbox.org

My work is now entirely in VirtualBox VMs. I am using 4.3.30, and would like to move to 5.0.6, but wonder mainly two things:
1. Has anyone experienced any severe issues in making the transition?
2. If I find a problem, will 5.0.6 have modified the VDI files, preventing me from reverting to 4.3.30?

Thanks!

I suggest you make a snapshot of vm, then install the new version of Virtualbox, and test it.
If it goes wrong, you can revert to the snapshot.