LittleFS - Fatal Python error: initfsencoding: unable to load the file system codec ModuleNotFoundError: No module named 'encodings'

[sjgcornish]

I would appreciate some help with this.
I installed python 3.13 with the setting set path and removed and reinstalled the arduino-pico core
path = C:\Users\sjgco\AppData\Local\Programs\Python\Python313
I also tried setting PYTHONHOME and PYTHOMPATH to the same but with no change in the error
I can start python from the command line
C:\Users\sjgco>python
Python 3.13.7 (tags/v3.13.7:bcee1c3, Aug 14 2025, 14:15:11) [MSC v.1944 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.

The arduino-core install... (Arduino IDE 2.3.6)

Installing rp2040:[email protected]
Configuring tool.
rp2040:[email protected] installed
Installing rp2040:[email protected]
Configuring tool.
rp2040:[email protected] installed
Installing rp2040:[email protected]
Configuring tool.
rp2040:[email protected] installed
Installing rp2040:[email protected]
Configuring tool.
rp2040:[email protected] installed
Installing rp2040:[email protected]
Configuring tool.
rp2040:[email protected] installed
Installing rp2040:[email protected]
Configuring tool.
rp2040:[email protected] installed
Installing rp2040:[email protected]
Configuring tool.
rp2040:[email protected] installed
Installing platform rp2040:[email protected]
Configuring platform.
Platform rp2040:[email protected] installed

Where does arduino IDE and or LittleFS look to find python.
.
Thank you for any assistancein resolving this

Steve

[earlephilhower]

If you are using the IDE then you do not need to install Python globally, it's part of the tools that are put into the core package directory (it's a portable, non-global version). If you are using Platform.IO then you need Python running just to run that wrapper and again, nothing special to install here.

The error looks like you have an old core version where the Windows uninstall wasn't done right on an upgrade. Remove it from the IDE, exit the IDE and log out (to ensure no hanging processes left) and log back in and install the latest version. #2853 basically rewrote part of the core to work around the IDE/Windows issue. 4.5.1 or later has that patch.

[sjgcornish]

Hi Thank you for you quick response
I uninstalled 4.5.0 restarted windows and installed 4.71.
Now when I include LittleFS.h and when I select the FSUpload example i get the error when trying to compile, befor I got the error on the example only when trying to upload.

Fatal Python error: initfsencoding: unable to load the file system codec
ModuleNotFoundError: No module named 'encodings'

Current thread 0x00003770 (most recent call first):
exit status 0xc0000409

Compilation error: exit status 0xc0000409

[sjgcornish]

The error at compile time was because I selected the MBed Core (note Mbed LittleFS works fine)
I runinstalled 4.7.1 log out the reinstalled still same error on uploading littleFS file

[sjgcornish]

LittleFS Filesystem Uploader v1.1.8 -- https://github.com/earlephilhower/arduino-littlefs-upload

Sketch Path: C:\Users\sjgco\AppData\Local\Temp.arduinoIDE-unsaved2025716-12904-cnnq2r.ev88\FSUpload
Data Path: C:\Users\sjgco\AppData\Local\Temp.arduinoIDE-unsaved2025716-12904-cnnq2r.ev88\FSUpload\data
Device: RP2040 series

Building LittleFS filesystem
Command Line: C:\Users\sjgco\AppData\Local\Arduino15\packages\rp2040\tools\pqt-mklittlefs\4.1.0-1aec55e\mklittlefs.exe -c C:\Users\sjgco\AppData\Local\Temp.arduinoIDE-unsaved2025716-12904-cnnq2r.ev88\FSUpload\data -p 256 -b 4096 -s 262144 C:\Users\sjgco\AppData\Local\Temp\tmp-10692-bcqzPv8yy56J-.littlefs.bin

Uploading LittleFS filesystem
Command Line: C:\Users\sjgco\AppData\Local\Arduino15\packages\rp2040\tools\pqt-python3\1.0.1-base-3a57aed\python3.exe C:\Users\sjgco\AppData\Local\Arduino15\packages\rp2040\hardware\rp2040\4.7.1\tools\uf2conv.py --base 270266368 --serial COM4 --family RP2040 C:\Users\sjgco\AppData\Local\Temp\tmp-10692-bcqzPv8yy56J-.littlefs.bin
Fatal Python error: initfsencoding: unable to load the file system codec
ModuleNotFoundError: No module named 'encodings'

Current thread 0x00002914 (most recent call first):

[earlephilhower]

That looks like it was still not properly and completely removed before reinstallation. You can use the heavy hammer way.

Uninstall again from the IDE. Exit it. Go to the folder C:\Users\sjgco\AppData\Local\Arduino15 in Explorer and delete the entire packages folder. Restarting the IDE and reinstalling the core should cause it to downstairs and into the file once again

[sjgcornish]

That worked ! Many thanks for your help