Hi guys 
Some of you may encounter a problem after upgrading OctoPrint to 1.9.2 which prevents OctoPrint from starting.
We think the issue is related to a recent pydantic update - a dependency of OctoPrint.
Here's a quick solution for OctoPi users which should hopefully fix the issue for you in a few minutes:
- SSH into the Pi
(if you need help with that part and you're a Windows user checkout this guide or this guide for Mac users).
The credentials are (assuming you didn't change them): username: pi | password: raspberry - run the following commands line by line
sudo service octoprint stop
source /home/pi/oprint/bin/activate
pip install pydantic==1.10.12
deactivate
sudo service octoprint start
- wait a minute for OctoPrint to start up and try to connect to the WebUI again
If that doesn't work for you, try to downgrade OctoPrint to 1.8.7 for now. Some users reported that solved the issue for them
- SSH into the Pi
- run the following commands line by line
sudo service octoprint stop
~/oprint/bin/pip install --force-reinstall OctoPrint==1.8.7 --no-cache-dir
sudo service octoprint start
- wait a minute for OctoPrint to start up and try to connect to the WebUI again
if you aren't running OctoPi please change the paths to your venv accordingly
@foosel will investigate the issue further next week and release an update as soon as possible.