HomeAssistant setup as per https://www.home-assistant.io/integrations/repetier<br/>This is the setup:

#RS
repetier:
 - host: 127.0.0.1
 api_key: KEY_HERE

camera:
 - platform: mjpeg
 name: RS Camera
 still_image_url: http://127.0.0.1:8080/?action=snapshot
 mjpeg_url: http://localhost:8080/?action=stream

The HA Log reports an error with the RS integration, it is missing "activeExtruder":

Logger: homeassistant.setup
Source: components/repetier/init.py:237 < https://github.com/marthoc/home-assistant/blob/dev/homeassistant/components/repetier/__init__.py >
First occurred: 10:06:59 PM (1 occurrences)
Last logged: 10:06:59 PMError during setup of component repetier

Traceback (most recent call last):
 File "/usr/src/homeassistant/homeassistant/setup.py", line 249, in async_setup_component
 result = await task
 File "/usr/local/lib/python3.9/concurrent/futures/thread.py", line 52, in run
 result = self.fn(*self.args, **self.kwargs)
 File "/usr/src/homeassistant/homeassistant/components/repetier/init.py", line 192, in setup
 api.update()
 File "/usr/src/homeassistant/homeassistant/components/repetier/init.py", line 237, in update
 printer.get_data()
 File "/usr/local/lib/python3.9/site-packages/pyrepetier/clsprinter.py", line 104, in get_data
 self.activeextruder = data['activeExtruder']
KeyError: 'activeExtruder'

It seems someone reported an issue earlier on another location - https://github.com/home-assistant/core/issues/59430 . this was working for me 2 days ago on the current HA version with RS 1.2.0; I updated to 1.2.1 today and noticed it was not; maybe something else is the cause?