How do I debug this?

I have been getting these for a while:

The log entry doesn’t tell me in which file the problem lies and I have dozens of files with multiple dozens of these DS18B20 sensors being monitored. Is there a way to set a debug level (or some other solution) so that HA will tell me where this issue is located?

can you paste you template here

do a search for DS18B20 in your template section

It looks like it’s throwing off the error every 15-16 seconds. I’d turn off 1/2 the devices and if error not ended then turn off 1/2 the devices left and keep going until narrowed it down to 1.
Alternatively if all your DS sensors are working learn to live with the error until someone fixes it.

Tracking because I too wonder if there’s a way to improve HA’s lackluster error messages. A good log message would include a unique id at least.

Assuming this is a template you’ve defined yourself, I would recommend editing every appearance of it to include a check that the DS18B20 attribute exists in the json before trying to use it, as kind of a best-practice error avoidance strategy.

value_template: "{{ value_json.DS18B20.temperature if value_json.DS18B20 is defined and value_jason.DS18B20.temperature is defined }}"

If you add an “else” to that line if you want to set a default value for the sensors not reporting temperature to narrow down which one it is.

Edited to add: while fixing, might as well also make sure “temperature” is defined in the value_json for additional error-checking (I haven’t verified my syntax above, feel free to correct).

I added the validity checks and else clause to set a value of -80 degrees to try to find the problem template. I modified all of my manually configured MQTT sensors. The problem still persists. From that, I presume that there are sensor definition(s) from integrations that have the problem but I have now way to see them.

I guess I would have to remove suspect integrations one by one until the problem goes away. That’s pretty painful unless there’s another way I don’t see.

Maybe also check whether you have template “helpers” defined in the UI rather than YAML?

Also I searched my logs and saw a similar error “helpers/” when I had a typo in an automation action template (!) so might also be worth searching all your automations for the DS18B20 string.