This is a common problem. I have had experience using VMware Workstation Pro v15, and I have also encountered several similar issues. I don't remember seeing an "Unknown Error" related to USB, but maybe it's just a bug in your version v15.0.2.10952284. They often allow this in their releases, and all I can advise you is to try reinstalling your VMware Workstation Pro. I've been using VMware for a long time now with a much better
app volumes documentation that doesn't have such primitive problems. This is unlikely, but it is also possible that you have outdated USB drivers, so I would check for updates for them if nothing helps.