This first bugfix release for 1.9.0 fixes a few bugs reported since the release of 1.9.0, and also improves one of the new features introduced in 1.9.0:

✨ Improvements

  • #4821: Defer sending of M20 until after the capability report has been received by default, instead of defaulting to sending it right away. Most firmwares out there now should be sending capability reports, and for those that don’t, the setting can still be manually set to false.

🐛 Bug fixes

  • #4818: Fix broken/erroring plugin sorting if a list of SortablePlugins and non sortable plugins gets processed in the same sorting context.
  • #4829: Fix URL used by the GCode Viewer’s worker to fetch info about the file to be rendered. It was not supporting custom prefixes on the URL yet (e.g., now it does.
  • #4834: Fix a bug in the GCode Viewer that resulted in a print not being rendered when loaded while the tab of the viewer was not focused.
  • #4824: Fix potential webcam unload/load switching when scrolling on the control tab. Could not always be triggered, but apparently was seen under some circumstances.
  • Fix the reload button of the GCode Viewer
  • Fix a bug in the GCode Viewer causing layers that were empty in one file causing that layer to not be rendered in all consecutively loaded files, until a page reload.

You can also take a look at the short changelog on GitHub.

Like every single release (and release candidate) of OctoPrint ever since early 2016 this release was made possible only through your continued support of my work 💕

Issues while updating?

On every new OctoPrint release we see some people run into the same issues with outdated or broken environments all over again. If you encounter a problem during update, please check this collection of the most common issues encountered over the past couple of release cycles first, and test if the included fixes solve your problem.


The heads-ups from 1.9.0 still apply, please read them carefully, they might impact you and how you use OctoPrint! Also see the Further Information and Links below for more information, where to find help and how to roll back.


Thanks to everyone who contributed to this bugfix release and provided full, analyzable bug reports, suggestions and feedback!

A special Thank You! to these 2 fine people for their PRs!

Further Information

If connected to the internet, OctoPrint will allow you to apply this update automatically via an update notification. It may take up to 24h for this notification to pop up, so don't be alarmed if it doesn't show up immediately after reading this. You can force the update however via Settings > Software Update > Advanced options > Force check for update.

If your update fails chances are high you are running into one of the common update issues listed with fixes here, so please go through that FAQ entry first.

If you have any problems with your OctoPrint installation, please seek support on the community forum.