Launching a game

The launch is refused outright

Message	Cause	Fix
No host available	No host is online or able to serve it.	The browser retries for 20 seconds. Then check Admin ▸ Fleet ▸ Hosts.
Capacity exhausted	Hosts are full (encode slots or GPU memory).	Retry when something ends.
Host not ready	A readiness check blocks the host.	Open the host’s readiness card and fix the check, or press Launch anyway. See When a check blocks launches.
Home conflict	The user’s home for this app is claimed in more than one place, or can’t be confirmed.	See Admin ▸ Fleet ▸ Storage ▸ Home ownership. If the host is gone for good, release the claim.
Session quota exceeded	The user is at their session limit.	End one, or raise the limit in Admin ▸ People ▸ Users. A limit of 0 blocks everything.
Home in use	This app is already running for the user elsewhere.	End that session.
No app access	No grant for this user and app.	Grant it in Admin ▸ Library ▸ Apps.

Capacity looks free but launches are refused

• A blocking readiness check keeps the host or GPU out. Check its readiness card.
• The launch is pinned: a user with a home on one host always launches there, and an app’s placement can limit hosts.
• GPU memory: admission needs 1024 MB free by default. On small or integrated GPUs, lower it or turn it off:

QUASAR_VRAM_MIN_FREE_MB=512   # or 0 to admit on encode slots alone

The session starts, then fails immediately

The app container exited. See the reason in Admin ▸ Sessions and the app container’s logs. Common causes:

• No network. Apps get none by default. Set network: bridge on its runtime preset.
• Not a Quasar-family image. App images must build on Quasar’s graphics base layer.
• The app crashed. Check its logs.

The session stays running but shows a frozen frame

The app’s exit policy is keep, which holds the session open. Use fail (the default).

Steam will not start

Symptom	Fix
“Steam needs to be” in the agent log	Steam has no network. Set network: bridge on the Steam runtime preset.
Steam starts, no games found	Discovery finds installed games only. Install one through the Steam launcher, then rescan from Admin ▸ Library ▸ Sources. The host needs a managed-home root set to a host path (Admin ▸ Fleet ▸ Hosts). See The Steam library.
The Steam image won’t install	Check the job in Admin ▸ Fleet ▸ Jobs: usually registry reachability, a registry outside QUASAR_IMAGE_REGISTRY_HOSTS, or an image contract failure.

The game runs at the wrong resolution

Quasar passes QUASAR_STREAM_WIDTH, QUASAR_STREAM_HEIGHT, QUASAR_STREAM_FPS and GAMESCOPE_* equivalents to the app. If the app’s runtime preset sets them explicitly, that value wins; remove it.

Nothing is in the library

Users see only apps they’re granted. Discovered apps are granted to everyone; apps you create by hand aren’t. Check the app exists in Admin ▸ Library ▸ Apps.

Controllers are not detected

Press a button: browsers hide a gamepad until it sends input. In Steam Big Picture, a button press also gives it focus. More in Picture, sound and input.