Getting error: Unknown error validating config for template platform for sensor component with PLATFORM_SCHEMA

Hi,
When I try to check the configuration by pushing the button, I get several errors and the validation seems to never end.

It is important to note that my system works perfectly well.

A little help or some direction to investigate would be appreciated.

Denis

By checking the log, I get these error messages:

Logger: homeassistant.config
Source: helpers/config_validation.py:736
First occurred: 10:06:56 AM (1 occurrences)
Last logged: 10:06:56 AM

Unknown error validating config for template platform for sensor component with PLATFORM_SCHEMA
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/config.py", line 855, in async_process_component_config
    p_validated = platform.PLATFORM_SCHEMA(p_config)  # type: ignore
  File "/usr/local/lib/python3.8/site-packages/voluptuous/validators.py", line 218, in __call__
    return self._exec((Schema(val) for val in self.validators), v)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/validators.py", line 337, in _exec
    v = func(v)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 272, in __call__
    return self._compiled([], data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 817, in validate_callable
    return schema(data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 272, in __call__
    return self._compiled([], data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 594, in validate_dict
    return base_validate(path, iteritems(data), out)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 386, in validate_mapping
    cval = cvalue(key_path, value)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 817, in validate_callable
    return schema(data)
  File "/usr/src/homeassistant/homeassistant/helpers/config_validation.py", line 485, in verify
    return cast(Dict, schema(value))
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 272, in __call__
    return self._compiled([], data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 594, in validate_dict
    return base_validate(path, iteritems(data), out)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 386, in validate_mapping
    cval = cvalue(key_path, value)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/validators.py", line 215, in _run
    return self._exec(self._compiled, value, path)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/validators.py", line 339, in _exec
    v = func(path, v)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 817, in validate_callable
    return schema(data)
  File "/usr/src/homeassistant/homeassistant/helpers/config_validation.py", line 736, in validator
    if key in config:
TypeError: argument of type 'NoneType' is not iterable

Then this one:

Logger: aiohttp.server
Source: helpers/config_validation.py:736
First occurred: 10:08:20 AM (1 occurrences)
Last logged: 10:08:20 AM

Error handling request
Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/aiohttp/web_protocol.py", line 422, in _handle_request
    resp = await self._request_handler(request)
  File "/usr/local/lib/python3.8/site-packages/aiohttp/web_app.py", line 499, in _handle
    resp = await handler(request)
  File "/usr/local/lib/python3.8/site-packages/aiohttp/web_middlewares.py", line 119, in impl
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/security_filter.py", line 56, in security_filter_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/request_context.py", line 18, in request_context_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/ban.py", line 74, in ban_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/auth.py", line 135, in auth_middleware
    return await handler(request)
  File "/usr/src/homeassistant/homeassistant/components/http/view.py", line 131, in handle
    result = await result
  File "/usr/src/homeassistant/homeassistant/components/config/core.py", line 29, in post
    errors = await async_check_ha_config_file(request.app["hass"])
  File "/usr/src/homeassistant/homeassistant/config.py", line 898, in async_check_ha_config_file
    res = await check_config.async_check_ha_config_file(hass)
  File "/usr/src/homeassistant/homeassistant/helpers/check_config.py", line 223, in async_check_ha_config_file
    p_validated = platform_schema(p_validated)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/validators.py", line 218, in __call__
    return self._exec((Schema(val) for val in self.validators), v)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/validators.py", line 337, in _exec
    v = func(v)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 272, in __call__
    return self._compiled([], data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 817, in validate_callable
    return schema(data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 272, in __call__
    return self._compiled([], data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 594, in validate_dict
    return base_validate(path, iteritems(data), out)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 386, in validate_mapping
    cval = cvalue(key_path, value)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 817, in validate_callable
    return schema(data)
  File "/usr/src/homeassistant/homeassistant/helpers/config_validation.py", line 485, in verify
    return cast(Dict, schema(value))
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 272, in __call__
    return self._compiled([], data)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 594, in validate_dict
    return base_validate(path, iteritems(data), out)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 386, in validate_mapping
    cval = cvalue(key_path, value)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/validators.py", line 215, in _run
    return self._exec(self._compiled, value, path)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/validators.py", line 339, in _exec
    v = func(path, v)
  File "/usr/local/lib/python3.8/site-packages/voluptuous/schema_builder.py", line 817, in validate_callable
    return schema(data)
  File "/usr/src/homeassistant/homeassistant/helpers/config_validation.py", line 736, in validator
    if key in config:
TypeError: argument of type 'NoneType' is not iterable

Did you ever found out what caused it? I have a similar problem now…