This third RC of 1.4.0 fixes some regressions and issues in the new functionality observed with the first and second one:


  • #3367 - Ensure that static CSS and JS files always get the correct MIME Type associated, to work around issues when installed under Windows 10 with invalid entries in the registry triggering strict MIME checking
  • #3381 - Continue to support request parameters on the /api/login endpoint for now for backwards compatibility with API clients that still use things like /api/login?passive=true, e.g. older versions of Printoid
  • Remove a left-over comment from the Python 3 migration

Bug fixes

  • #3365 (regression) - Fix permissions of global API key
  • #3366 (regression) - Appkeys: Fix issue causing 500/internal server error
  • #3370 (regression) - Fix issue causing lost session in case of a client IP change
  • #3371 - Python 3: Fix calculation of rolling_window in print time estimator
  • #3375 - Fix abort support for SimpleApiPlugin implementations
  • #3384 - Python 3: Fix login using HTTP Basic Auth
  • #3385 - Python 3: Fix serial port auto detection
  • #3388 - Granular permission system: Fix extruder controls being visible without control permission
  • Fix a unicode issue under Windows (regression)

The heads-up regarding Plugins and Python 3 from 1.4.0rc1 still applies.

You can find the full changelog and release notes as usual on Github.

Special thanks to everyone who contributed to this release candidate and provided full, analyzable bug reports!

As the past RCs have shown me that a lot of people appear to be unaware of this: Please do not install this RC if you expect a fully stable version. It is not a stable release, it is a release candidate, and of the next big release to boot: severe bugs may occur, and they might be bad enough that they make a manual downgrade to an earlier version necessary - maybe even from the command line.

You should feel comfortable with and capable of possibly having to do this before installing an RC.

If you want to and can help test this release candidate, you can find information on how to switch to the “Devel RCs” release channel in this guide if not already done (also linked below). Please note that contrary to maintenance releases this RC is not available on the “Maintenance RCs” release channel so if you are tracking that you’ll need to switch. The reason is that RCs of big releases might be more unstable at first than pure maintenance releases due to newly introduced features or very heavy refactorings, so I’m splitting these between two release channels. Note that when tracking “Devel RCs” you’ll get all releases from “Stable” and “Maintenance RCs” as well.

Please provide feedback on this RC. For general feedback you can use this ticket on the tracker. The information that everything works fine for you is also valuable feedback 😄. For bug reports please follow “How to file a bug report” - I need logs and reproduction steps to fix issues, not just the information that something doesn’t work so make sure to fill out all fields of the issue template.


Depending on the feedback regarding this version I’ll look into fixing any observed regressions and bugs and pushing out a follow-up version as soon as possible and necessary - due to the upcoming holidays 🎄 that will probably take until January however.