Printer won't connect to Octoprint after update

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1

What is the problem?

I just turned my printer back on after a few months. I got the message that updates are available so I pressed update which worked fine. Then I got the message that my python is nearing the end-of-life I looked up how to update that. I made a backup and reinstalled Octo print on my Raspberry pi 4. After uploading the backup, I noticed that my Octoscreen isn’t working anymore and I just get the classic Linux terminal. When restarting my printer and the raspberry PI I get the error message: “No more candidates to test, and no working port/baudrate combination detected.” Earlier then going Truong my settings Octoprint even found the port my printer was connected to when trying to switch between Auto and a specific por. Not it doesn’t even show that anymore. When trying to connect my printer to my pc running printer face I get some garbage messages since Klipper is relying on the raspberry pi to communicate to my PC.

What did you already try to solve it?

Connecting directly to Pronterface
Restarting multiple times
messing around with settings in Octoprint

Have you tried running in safe mode?

No

Did running in safe mode solve the problem?

No

Systeminfo Bundle

browser.user_agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36
connectivity.connection_check: 1.1.1.1:53
connectivity.connection_ok: True
connectivity.enabled: True
connectivity.online: True
connectivity.resolution_check: octoprint.org
connectivity.resolution_ok: True
env.hardware.cores: 4
env.hardware.freq: 1800.0
env.hardware.ram: 3968630784
env.os.bits: 32
env.os.id: linux
env.os.platform: Linux-6.6.51+rpt-rpi-v7l-armv7l-with-glibc2.36
env.plugins.pi_support.model: Raspberry Pi 4 Model B Rev 1.5
env.plugins.pi_support.octopi_camera_stack: webcamd
env.plugins.pi_support.octopi_version: 1.1.0
env.plugins.pi_support.octopiuptodate_build: 1.1.0-1.11.3-20250909113029
env.plugins.pi_support.octopiuptodate_build_short: 2025.09.09.113029
env.plugins.pi_support.throttle_check_enabled: True
env.plugins.pi_support.throttle_check_functional: True
env.plugins.pi_support.throttle_state: 0x0
env.python.pip: 25.0.1
env.python.version: 3.11.2
env.python.virtualenv: True
octoprint.last_safe_mode.date: 2025-05-04T09:17:18Z
octoprint.last_safe_mode.reason: incomplete_startup
octoprint.safe_mode: False
octoprint.version: 1.11.3
systeminfo.generated: 2025-10-18T10:25:06Z
systeminfo.generator: zipapi

Additional information about your setup

Octoprint version: 1.11.3
OctoPi version: 1.1.0
Printer: JG Aurora A5
MCU / Printerboard: MKS Gen_L V2.1
Raspberry Pi 4 + Raspberry Pi Cam + Raspberry pi screen

2

Hallo @phUCh5 !

Please attach the systeminfo bundle to your next post.

3

octoprint-systeminfo-20251018122506.zip (17.7 KB)
Here my Systeminfobundle.
Today as I opened octoprint.local I got the error message that my printer.cfg is missing. Even after trying to re upload my latest backup I still get the same error message.

4

So you are running Klipper?
What OctoPrint/Klipper setup do you use?

When running Klipper, OctoPrint connects to Klipper and Klipper connects to the printer.

5

Ou hmm that was a long time ago when I set that up. As far as I can remember I am running klipper but it only controls my steppers and does not calculate any of the movements from the gcode. The calculations are completely done by the raspberry pi

6

I just uploaded a Backup of my Printer.cfg and now it at least detects my printers usb port but I still can't connect to it. The error message I get is "no more candidates to test".

Screenshot 2025-10-19 143138
Screenshot 2025-10-19 143138699×224 5 KB

7

When you have Klipper on the printer, you do not connect OctoPrint to the Print, but to Klipper.
Usually this is serial port /tmp/printer.
Within the printer.cfg is the information how Klipper connects to the printer.

8

I'm having the exact same issue. Has there been any resolution?

9

Hello @Timothy_Keziah !

Please have a bit patience. This thread is not that old.
To give us a helping hand, you may describe your issue in more detail.
From our experience, there is no

10

So, I just took a look at my printer.cfg and I have this set as my serial connection.

[mcu]
serial: /dev/serial/by-id/usb-1a86_USB_Serial-if00-port0

thanks for helping

edit:
I just checked if the serial port has changed but doesn't seem like it

pi@octopi:~ $ ls /dev/serial/by-id/*
/dev/serial/by-id/usb-1a86_USB_Serial-if00-port0

11

Same issue. Everything was running fine for 4 years, got the notification that python was EOL and to upgrade. Did a backup/reinstall of octoprint/restore and about 90% of the time the printer wont connect to octoprint (Its plugged in via serial over GPIO pins on a raspi3B)

randomly if i reboot the octoprint and the printer over and over it sometimes connect. but 30-60 minutes of fiddling is a nightmare before every print.

Is somethign wrong with the new release? *
OctoPrint 1.11.3
Python 3.11.2
OctoPi* 1.1.0 (build 2025.06.10.114348
octoprint-systeminfo-20251023183027.zip (20.4 KB)
octoprint-logs_2.zip (81.4 KB)