Hi. I just upgraded to Mac OS 10.13 High Sierra and then upgraded to Fusion 10 from Fusion 6. My guest machine is Windows 7 64-bit. Under Fusion 6 and Mac Yosemite, I could plug in a USB device and Fusion would ask me which system I wanted to connect it to. After the upgrade, it would only connect to Mac and didn't give me the choice any more.
I just spoke to support and they solved it immediately. It appears to be the Mac blocking something, not a problem with VMWare. They are in touch with Apple and will be addressing this in the next release. There were two main steps, but I think it was really the second step that did it.
1. Shut down the guest Windows machine (not suspend). In the Fusion window, right click the name of the guest machine and choose Settings. Then click USB & Bluetooth. Then click Advanced USB options. Then click Remove USB Controller. Open the Windows guest machine and then shut it down again (not suspend). Go back to USB & Bluetooth in Fusion Settings for the guest machine and this time click Add USB Controller.
2. Click the Apple logo in the top left of the Mac screen. Click Security & Privacy. For me, there was an error message that said something like "Mac is blocking VMWare process". Click Allow. Problem solved.
As I said, I think it was probably just the second step, but that's what worked for me.
