Your system information

• SteamVR Version: 1487744123 ( 2017-02-22 )
• Distribution : Xubuntu 16.04.2 LTS
• Opted into Steam client beta?: Yes
• Have you checked for system updates?: Yes

Please describe your issue in as much detail as possible:

lanching the steam VR it gives me the following error message screenshot

driver installed using suggested PPA

Tracking is working, also controllers are recognized... and display turn on if I set HDM as extended monitor in X11.

Steps for reproducing this issue:

1. clicking start on SteamVR from Steam
2. waiting