Hi @ines,
I'm running into the same problem, but the css setting doesn't work for me. I'm running a custom coref recipe and it works but six texts in it encounters the following error:
and my prodigy.json file is empty except for {} - screenshot below:
I added "card_css": {} between the two brackets and it runs, but still gives the error message. I replaced everything with only "card_css": {} and then it doesn't start the server.
I'm running prodigy 1.11.4 on Windows 10 with Python 3.9.6.