Hi ! Just copy-pasting the answer I posted on GitHub at Unable to resolve any data file after loading once · Issue #3431 · huggingface/datasets · GitHub, in case anyone has a similar issue:

Hi ! load_dataset accepts as input either a local dataset directory or a dataset name from the Hugging Face Hub.
So here you are getting this error the second time because it tries to load the local wiki_dpr directory, instead of wiki_dpr from the Hub. It doesn’t work since it’s a cache directory, not a dataset directory in itself.
To fix that you can use another cache directory like cache_dir="/data2/whr/lzy/open_domain_data/retrieval/cache"