Disk Utility and diskutil in Terminal having errors formatting SanDisk USB drive 30 - 32 gigs

If it is connected via a hub, try it directly connected.

Try it on another computer.

In Disk Utility, click the View button at the top of the disk list and choose Show All Devices.

You should see your SanDisk device listed along with any volumes (partitions).

Select the Device and try to erase it.