Thank you @Chrisir and @PhilHaw for your replies. The code is exactly the example from the loadStrings reference, that’s why I didn’t copy it. I tried this yesterday, went round several times, trying the list.txt alternately in the data folder and the sketch folder. The sketch only read it from the sketch folder. Today it’s reading from either. (PC is W10, frequently updated.) Alright, the help should say something like “it looks for the file first in the data folder and then in the sketch folder”. I think the words “must be loaded in” are unhelpful.
dataPath("") - I’d never heard of that, and it’s not in the reference.