Catch up on the latest product updates, best practices, and expert insights from the Checkmk Conference #12 – Watch the livestream recordings now

Werk #20070: Windows agent: Ensure Python is ready before starting agent updater

Component Checks & agents
Title Windows agent: Ensure Python is ready before starting agent updater
Date Jun 15, 2026
Level Trivial Change
Class Bug Fix
Compatibility Compatible - no manual interaction needed
Checkmk versions & editions
3.0.0b1
Not yet released
Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

On Windows agents, the agent controller invoked agent updater registration could fail if it was started immediately after agent installation. The agent controller then logged:

[Err  ] Python Module is not installed
Agent Updater registration failed

The updater depends on the bundled Python runtime, which may still be in preparation right after installation. If registration started too early, Python was not available yet.

This has been fixed. The Windows agent now waits until the required runtime components are ready before running updater registration. This covers both automatic and manual registration started immediately after installation.

Agents baked without the Python module still report the missing Python module immediately.

Hosts where updater registration already failed are not retried automatically. To register the updater, de-register the controller, for example with cmk-agent-ctl.exe delete-all, and let auto-registration run again, or register the updater manually as described in Werk #20067.

To the list of all Werks