Lab stopped unexpectedly

A lab you left running is stopped, paused or gone. The Activity tab almost always says why. Read it first, then find the cause below.

Reading the Activity tab

Open the lab and go to Activity. Each event shows what happened, when, and who or what caused it.

Event	Meaning	Section
Auto-stopped · expiry	The lab reached its session time limit or was idle too long	Expiry and idle shutdown
Auto-stopped · high CPU	It used too much CPU for too long	High CPU
Out of memory (OOM)	A process used more memory than the lab has	Out of memory
Crashed · exit N	The lab's main process exited	Crashed
Stopped unexpectedly	The machine was removed or crashed outside a normal stop	Crashed
Admin stopped it	An administrator stopped it	Ask your administrator
Paused	It was frozen — by you, or by the platform	Paused by the platform
Health check failing / Health recovered	The lab's health check stopped passing, or started again	Health check
Auto-started · always-on	Always-on brought it back after a stop	Nothing to do
Started, Redeployed, Stopped, Resumed	Normal lifecycle, with who did it	—

Actions taken by an AI assistant connected through MCP are marked as such.

Expiry and idle shutdown

Session limits. Some labs — most challenge labs — run for a fixed time. While running they show an Expires in timer. You can Renew a running or paused lab from its page, spending Jolt for more time; the dialog shows the cost and how much time you get.

Redeploying after a renewal loses the time you bought

Renew, then keep working in the same session. A redeploy starts a fresh session.

Idle shutdown. Running labs with no activity for a long stretch are stopped — after about a week on the free plan and about a month on a paid plan. Your home directory is kept; deploy again to continue.

To keep a lab up regardless, turn on always-on (requires the template to allow it, and a paid plan or 5,000 Zeal).

High CPU

Sustained heavy CPU use is watched. The sequence is:

1. A notification that the lab is running throttled.
2. A notification that it is about to be stopped.
3. If the load continues, the lab is stopped — Auto-stopped · high CPU. Running challenge missions in it fail.

The lab's Dashboard tab shows CPU throttle %. 0% is healthy; a high figure means the lab is being held back, not just busy.

Fix it by finding the process (top or htop in the lab), stopping runaway loops or builds, and limiting parallel jobs (make -j2, fewer workers).

Out of memory

Out of memory (OOM) means a process asked for more memory than the lab has, and was killed. Often the lab keeps running without that process; sometimes the lab stops.

• Check the lab's memory figure on its Dashboard tab.
• Look for the process that grows — top, sorted by memory.
• Reduce it: fewer workers, smaller caches, a smaller data set, or a database from Services instead of one inside the lab.

Memory comes from the lab's template and your plan; there is no slider.

Crashed or stopped unexpectedly

The lab's main process exited, or the machine went away without a normal stop.

1. Redeploy.
2. If it happens again, test your startup script with Run now — a script that fails can stop the lab coming up.
3. Check the Deployments tab for a failed attempt — see Deploy failed.

Paused by the platform

If your subscription lapses, the platform pauses your labs. Trying to resume shows This lab was paused by the platform (subscription). Renew your plan to resume it. Renewing lets you resume it with everything intact.

A lab you paused stays paused until you click Resume — always-on does not resume it, on purpose.

Health check failing

Labs whose template defines a health check report when it stops passing. In a scale group, a failing replica is taken out of rotation until it recovers. Check the app inside the lab is running and answering on the health-check path.

Your account was inactive

After a year without signing in, a free account's devices are suspended and its storage retired. Signing in again restores them.

Next

• Stop, pause and delete
• Lab settings — always-on and the startup script
• Deploy failed