That implies the document loader isn't either right or there's nothing for it to load. You should check for both

You can replace the loader with unstructured url loader:

from langchain.document_loaders import UnstructuredURLLoader

def ingest_docs():
"""Get documents from web pages."""
loader = UnstructuredURLLoader(urls=["https://python.langchain.com/en/latest/"])
raw_documents = loader.load()

This works awesome! Solved it on my end