Compositor is not available

[Tomz]

So i got the VIVE yesterday and i had to get a MDP to DP cord because my PC only has 1 hdmi port.
I finally got everything installed and loaded SteamVR. It all setup fine untill i got a Not Ready witht the error Compositor is not available(400). i also got a popup that had an error 306.
I have reinstalled all Vive and SteamVR software, rolled back my graphics driver settings (got Nvidia Geforce 970x)
Tried enabling direct mode.
whenever i unplug my monitor and use hdmi for my vive nothing works (i remote accessed and none of the steamvr things work)
Ive been trying to fix it for over 2 hours now. I need some help.

[Alien Identity]

You need both the Vive and Monitor working at the same time...... use the HDMI for the Vive, and get an adaptor to run the Monitor off the other output..... the Vive may not work if attached to an adaptor, some work some dont.

[Tomz]

so that could be my only problem? just switch those around? hopefully is because if not ill have to return it :(

[Alien Identity]

https://www.mwave.com.au/product/alogic-1m-mini-displayport-to-displayport-cable-ver-12-mm-ab88674

This DisplayPort to Mini-DisplayPort cable works with my 1080ti and the Vive...... connects the Video Card to the Vive Breakout Box.

[Tomz]

i did something last night and it worked but now its got the same error.
I have a MDP to dp for the vive. both monitor and vive are on the same graphics card

[Alien Identity]

Check the minidisplayport connection.... any little bump can make it loose.

[Tomz]

i got my screen to show finally but its just my desktop screen nothing else. my newest error was compositor is not fullscreen

[Tomz]

and now its back to compositor not available. everything is plugged in correctly. no loose cables...

[Alien Identity]

Try.... disconnect USB from computer..... restart computer, plug in USB again, and see if it is recognised.

In SteamVR (on the desktop window.......click on the little trianghle/arrow to open dropdown menu) go to settings...... then Developer....... look for reset... remove all SteamVR USB devices. If you disconnect the USB, then do the Reset SteamVR USB Devices....... then plug the USB back into a DIFFERENT USB port. .... wait till it is recognised and installed.See if it helps.

[Tomz]

okay so i just ran out and got a dp to hdmi for my monitor and have htc vive in hdmi and it worked, but now i have no display on the headset

[Alien Identity]

Uninstall/Reinstall SteamVR after replacing or changing cables.

[Tomz]

i managed to get it working without reinstalling everything for a 3rd time. as soon as i enabled direct mode and disabled power management it worked

[Alien Identity]

Glad you got it running OK.

[Solyc Cλndy]

Everyday I get this error. EVERY DAY. And I've the cables connected properly.

With Vive Pro here.

I just "reboot vive headset" or restart windows. It works after some times, maybe 2, maybe 5, maybe at the first attempt. Just lottery. What's happening?