Was finally able to get something that didn’t crash by getting rid of the y_block argument, adding a “bs=64” parameter (which I doubt makes a lot of difference), so that it now looks like the following:
x["correct"] = x["correct"].astype(int)
dls = TabularDataLoaders.from_df(x, procs=procs, cat_names=cat_names, cont_names=cont_names,
y_names="correct", valid_idx=valid_idx, bs=64, metrics=f1_score)
I have no idea why that works whereas the earlier version doesn’t, but regardless, perhaps this may help someone else.