Filter sensor. Unused name won't go away!

I’ve been testing some filters in my sensors file.
One of them had an error, as you can see here:

File “/usr/local/lib/python3.6/site-packages/homeassistant/”, line 673, in init
“State max length is 255 characters.”).format(entity_id))
homeassistant.exceptions.InvalidStateError: Invalid state encountered for entity id: sensor.vaskerom_temperatur_2. State max length is 255 characters.

Fair enough. But I deleted it, so the referred sensor doesn’t exist anymore! It has been removed. I’ve searched all files in my config folder.

I also have a filter that i tried to set precision: 0 in. It wasn’t allowed. I get this message in home-assistant.log:
TypeError: init() got an unexpected keyword argument ‘precision’

so I removed it .
But Hassio won’t forget it!, and the error message is still there!

Is there a file cache somewhere that’s being used?