Integration not loading on 2025.10.0: AttributeError: 'function' object has no attribute 'is_safe_callable'

[PeterPalenik]

The integration stopped working after upgrade to HA 2025.10.0. This is the error:

Error during setup of component custom_templates: 'function' object has no attribute 'is_safe_callable'
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/setup.py", line 425, in _async_setup_component
    result = await task
             ^^^^^^^^^^
  File "/usr/local/lib/python3.13/concurrent/futures/thread.py", line 59, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/config/custom_components/custom_templates/__init__.py", line 96, in setup
    TemplateEnvironment.ct_original_is_safe_callable = TemplateEnvironment.is_safe_callable
                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'function' object has no attribute 'is_safe_callable'

Looks like there's been a refactor of templates in HA Core that might have caused it.

[PiotrMachowski]

Huh, that's interesting, because I also have 2025.10.0 installed and it works fine... Can you check if you have the latest version installed?

[PeterPalenik]

Had the latest version. Tried reinstalling the latest one again but did not help. Still the same error message.

[PiotrMachowski]

What other custom integrations do you use?