Comment 13 for bug 1404147

Exact same problem. I've tried many online solutions but I can't get it to work.

Using an HDMI connection.

MSI GS43VR
GeForce GTX 1060/PCIe/SSE2
ubuntu 16.04 LTS
Nvidia binary driver 381.22 from nvidia-381 (open source)

Works:
- External monitor only

Does not work:
- First monitor only
- Extended mode
- Mirror mode

However, during my trial and error process, I got to manage to get everything except extended mode working.