Steps to reproduce:
1. Create a new project
2. Add the SpatialMapping_room.obj to the Assets folder
3. Go back to Unity and select the imported file
4. Check Generate UV and hit Apply
5. Observe the errors

Actual result: Unity throws the errors
Expected result: Unity should not throw the errors

Reproduced with: 5.6.3f1 , 2017.1.0p1, 2017.2.0b5, 2017.3.0a2
Not reproduced with: 5.5.4p2