my code to load was working jsut fine in

import nest_asyncio
from llama_index.core.extractors import TitleExtractor, QuestionsAnsweredExtractor
from llama_index.core.node_parser import TokenTextSplitter

nest_asyncio.apply()

# Configure text splitter
text_splitter = TokenTextSplitter(separator=" ", chunk_size=512, chunk_overlap=128)

# Load documents
documents = SimpleDirectoryReader("data/pdf").load_data()
storage_context = StorageContext.from_defaults(vector_store=vector_store)

# Create index
index = VectorStoreIndex.from_documents(documents, transformations=[text_splitter], storage_context=storage_context)
``