The download instructions for c4 datasets are not contained in the error message
Good catch !
Indeed the `@property` is missing.

Feel free to open a PR :) Also not that C4 is a dataset that needs an Apache Beam runtime to be generated.
For example Dataflow, Spark, Flink etc.

Usually we generate the dataset on our side once and for all, but we haven't done it for C4 yet.
More info about beam datasets [here](https://huggingface.co/docs/datasets/beam_dataset.html)

Let me know if you have any questions
The manual download instructions are not clear 
```The dataset c4 with config en requires manual data. 
 Please follow the manual download instructions: <bound method C4.manual_download_instructions of <datasets_modules.datasets.c4.830b0c218bd41fed439812c8dd19dbd4767d2a3faa385eb695cf8666c982b1b3.c4.C4 object at 0x7ff8c5969760>>. 
 Manual data can be loaded with `datasets.load_dataset(c4, data_dir='<path/to/manual/data>')
```

Either `@property`  could be added to C4.manual_download_instrcutions (or make it a real property), or the manual_download_instructions function needs to be called I think.

Let me know if you want a PR for this, but I'm not sure which possible fix is the correct one.