Raise "No file in this folder" when using download script.

Hi, I tried to use the download script provided by the repo for downloading, but it reported an error that there were no files in the folder. Is there any problem?

Log:
```
Password input complete, jumping
Fetching cookies
No file in this folder
```

Start by locating and running the repository's download script with the same steps that produced the reported log. Read the script's handling of the folder contents and the "No file in this folder" path; done means identifying the cause and adding a reproducible fix or clearer failure behavior.

Written by the indexing model from the issue text.