Hey guys,
I got the same error when I changed from USB 3.0 to 2.0, and a similar error when switching back to 3.0.
Here is how I solved both - they are caused by XML having duplicate or incorrect controller declaration:
The error in the original post:
Is caused by the following controller definition being duplicated:
And in particular by both definitions using the same slot:
To fix it, I removed the second controller definition (don't forget to backup your entire VM XML before you attempt this):