Bamboo remote agent offline or disabled in CI

A Bamboo agent only builds when it is both online and enabled. "Offline" means the agent process is not connected to the server; "Disabled" means an administrator turned it off. Either state removes it from scheduling.

What this error means

The Agents page lists the agent as "Offline" (grey) or "Disabled", and jobs that require its capabilities queue with no agent to run them.

Bamboo

Agent status: Offline
Last communication: 27 minutes ago
Jobs requiring this agent's capabilities cannot be built while it is offline.

Common causes

The remote agent lost its connection to the server

The agent JVM crashed, the host rebooted, or the network to the Bamboo server dropped, so the server marks the agent offline.

The agent was disabled administratively

Someone disabled the agent (for maintenance or to drain it), which stops it from accepting builds until re-enabled.

How to fix it

Restart the remote agent process

Log in to the agent host and check the agent service or JVM is running.
Restart the agent so it reconnects and re-registers its capabilities.
Confirm it shows "Online" on the Agents page.

Terminal

# On the agent host
java -jar atlassian-bamboo-agent-installer-<version>.jar https://bamboo.example.com/agentServer/

Re-enable a disabled agent

If the agent is Disabled rather than Offline, enable it from Agents in Bamboo administration so it starts taking jobs again.

How to prevent it

Run the remote agent as a supervised service so it restarts on crash or reboot.
Alert on agents that go offline so gaps do not stall the queue.
Document maintenance disables so agents are not left disabled by accident.