Seems like there is some sort of strange bug in the USB driver on MacOS Sierra and Vuescan. I’ve been having trouble with hangs for a while and this seems to have gotten worse with Sierra, although El Capitan had the same issues. The calibrate for this 35mm image scanner takes forever.
Sigh. Old hardware doesn’t ever seem to work at some point. Looking at Vuescan, I do not see anything that can help, but I may switch back to firewire to see if this helps. I switched from Firewire (on an old iMac 2008) because I was having troubles with that driver. But with Sierra, it looks like Firewire 400 does not work anymore. The only thing that seems to help is a reboot of the system.
It could also be that it has to do with the hardware itself. The little door at the front can get stuck in the open position and it requires a paper clip to push it back in. Hardware from the last decade was like that!
As another aside, I did see that I should use the Vuescan dedicated Filter/Infrared Clean instead of ICE to get rid of scratches.