Terminal disconnects or does not open
The lab terminal runs in your browser and keeps a live connection to your environment. For normal use, see Use the lab terminal. Each problem below is laid out as Symptom, Cause and Fix.
“Terminal disconnected”
Section titled ““Terminal disconnected””Symptom. The terminal shows Terminal disconnected with a Reconnect button.
Cause. The connection between your browser and the lab was cut: an unstable network, a Wi-Fi change, a VPN reconnecting, or your computer going to sleep.
Fix. Select Reconnect. Your environment kept running while you were disconnected: files and resources you created are still there. A command that was running in the foreground may have been interrupted, so check its result.
“Terminal connection error”
Section titled ““Terminal connection error””Symptom. The terminal shows Terminal connection error and never connects, even after Reconnect.
Cause. Something between your browser and Klastro blocks the terminal’s live connection. This is common on corporate networks, behind some proxies and VPNs, or with strict browser extensions.
Fix.
- Reload the page.
- Try another network (a phone hotspot, for example) or turn the VPN off.
- Disable extensions that block or rewrite traffic for app.klastro.io, or try a private window.
- If you are on a company network, ask your IT team to allow secure WebSocket connections to app.klastro.io.
If none of this helps, report a problem and mention your browser and network.
The terminal stays on a waiting message
Section titled “The terminal stays on a waiting message”| Message | Cause | Fix |
|---|---|---|
| Waiting for session…, Provisioning environment…, Your environment is being prepared | The environment is still being prepared. | Wait. See Lab preparation. |
| Waiting for authorization… | The assessment waits for a recruiter’s approval. | Keep the page open; it continues once approved. |
| Waiting for shell URL… | The environment is ready but its terminal is still starting. | Wait a few seconds. If it lasts, reload the page. |
| Reconnecting… | The terminal is re-establishing the connection. | Wait. If it ends on Terminal disconnected, select Reconnect. |
| Invalid terminal URL | The page received a broken terminal address. | Reload the page. If it persists, report the problem. |
The terminal stopped accepting commands
Section titled “The terminal stopped accepting commands”Symptom. You can no longer type, and the lab shows This environment has ended or This environment is paused.
Cause.
- This environment has ended: the lab reached its time limit or was ended. It no longer accepts commands. Checks you had passed are kept.
- This environment is paused: in a class, your instructor moved you to another step. Your work is kept.
- In a self-paced lab, the lab may also have been paused because your credits ran out.
Fix. For a class, select Back to the class: the environment starts again when your instructor brings you back to that step. For credits, see Credits and paused labs. For an ended lab, start the scenario again.
Commands fail with “connection refused” or “command not found”
Section titled “Commands fail with “connection refused” or “command not found””Symptom. kubectl cannot reach the cluster, or a tool seems missing.
Cause. In labs with machines, the Shell tabs open the session shell: “kubectl, helm, and every machine within ssh reach. Not one of the machines.” Some commands must run on a specific machine.
Fix. Open the Node tab of the machine you need, or connect to it from a Shell tab with the ssh command shown under Connect to the machines. If the task tells you to work on a given machine, work on that machine.