Bed Visualizer reporting Type Error

What is the problem?

Bed Visualizer reports this error:
TypeError: null is not an object (evaluating 't[0]=(sL-lE+c*S)*C')

What did you already try to solve it?

A component restarted - not sure it that was Octopi, the Raspberry Pi 4 itself, or something else.

Logs (octoprint.log, serial.log or output on terminal tab at a minimum, browser error console if UI issue ... no logs, no support!)

Ok, I have logs, enabled every one I could find. What’s the smart way to make them available?

Octopi reports data for octoprint.log, plugin_bedlevelvisualizer_debug.log and serial.log

Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible)

I’m very new to 3D printing, Raspberry Pi and Octoprint. No prints to date - I’ve been battling with bed levelling (which has improved if Bed Visualizer is to be believed) and adhesion. I’m quite likely to say something that doesn’t make sense - purely out of ignorance.

I’m running a new (April 2020) Monoprice MP10 Mini with a USB connection to a Raspberry Pi 4 with the latest Octopi. Raspberry Pi is configured with a webcam of unknown pedigree - except for the fact that it’s new. I access the Octopi server from Firefox on an iPad Pro 2019 with all available updates applied.

Config details from Octopi:

"OctoPrint: 1.4.0
Installed: 1.4.0
Available: 1.4.0 (stable)
Release Notes:"

"ABL Expert Plugin: 0.6
Installed: 0.6
Available: 0.6"

"Autocalibration Plugin: 0.1
Installed: 0.1
Available: -"

"Bed Visualizer: 0.1.13
Installed: 0.1.13
Available: 0.1.13
Release Notes:"

"DisplayLayerProgress Plugin: 1.21.0
Installed: 1.21.0
Available: V1.21.0
Release Notes:"

"OctoPrint-BedLevelingWizard: 0.2.4
Installed: 0.2.4
Available: 0.2.4
Release Notes:"

"Resource Monitor: 0.2.3
Installed: 0.2.3
Available: 0.2.3
Release Notes:"

For debugging this one specifically I'll need the bedlevelvisualizer log and octoprint.log. You can either open an issue on the plugin's repo or drag/drop those into a comment here. It would also help to see the results of what is shown in the terminal tab when you run the autoleveling gcode command that you are using (ie G29 T). Also please include a screenshot of the plugin's settings.

Thanks for your response. <=== EDITED ===>

Ok, I finally figured out that I can attach files rather than paste their text into my reply. So, I’ve attached my Octoprint.log and BedVisualizer.log files.BedVisualizer and (243.0 KB)

I happened to look in my Serial.Log files, only to discover they consist only of a message telling me I did not have serial logging enabled. So I don’t have any useful information on that score. I have now enabled that logging, and I’ll check the files to make sure the content is more than another message about my errors.


Ok, so I don’t have a screenshot of Bed Visualizer settings as they were at the time. To be honest, I didn’t know there were any - they show up off-screen on my iPad, so I didn’t see them when I installed Bed Visualizer.

But I was very pleased and impressed when I did find them. I enabled display of the Angle Corrections, and set thread to M4 (after identifying it) and enabled one or two other settings, but I don’t remember which. Sorry.


I don't necessarily need thr serial log. You might want to turn that back off.

So I just looked at the logs and don't see any reason why this wouldn't be graphing for you, unless it's related to a webgl issue/unsupported graphics driver. It's possible it's iPad related as well, have you tried from another device yet?

Thanks for the feedback. I will try from my MacBook and let you know.


I tumbled upon this topic just to mention I met the same "TypeError: null is not an object ..." error by Bed Bisualizer on a Macbook Pro (MacOS Big Sur) running Safari. It works perfectly with Chrome on the same computer.