I have an Ubuntu 16.04 system and a Win 7 vdi from my previous computer. The first time I installed virtual box it installed 18.104.22.168. I installed extensions and guest additions for the same version. I got everything working in the VM but USB. I tried 2.0 and 3.0, neither change helped. I googled around a bit and found that I need to add my user to vboxusers group. I did that. Now I can see the usb devices in the device list but they aren't installing on my VM. What else might I need to do?
Update 1: I will add that it's not all USB devices as my mouse and keyboard still work but any storage device (4 differently branded thumb drives and 1 external HD) all do not get recognized. Weirder still, at least 2 of these thumb drives and the external drive worked when the VM was on my old machine.
Update 2: I failed to mention that after I tried the vboxusers group addition I updated everything to 5.1 Virtualbox and it still wasn't working.
Update 3: I tried claude's solution and that didn't work.
I suspect my VM is corrupted somehow so I spun up another VM (Windows 10 this time) and everything USB works on that. I've been slowly migrating all of my files and reinstalling apps over on the new VM.