Recent Marlin builds contain bugs that cause temperature reporting & serial issues

PLEASE READ: We are currently seeing a lot of issues on our support channels from people running into temperature reporting & serial issues with current Marlin firmware builds of the "nightly" and "bugfix" variant, e.g. as available on the Marlin Firmware Service at Those are caused by firmware issues, not OctoPrint. For more information on how to proceed see this post by @Charlie_Powell.


For what its worth, this was broken between 28th Jan and 1st Feb 2021. There are no known issues outside of this date range.

If you're using a build within this date range, it is suggested to update to a newer version which has corrected and completely re-written serial handling code.

To quickly quote myself from another thread: