I m getting this error ERROR IndexError

I'm getting this error"[ERROR] IndexError: list index out of range
Traceback (most recent call last):
  File "/var/task/app.py", line 85, in handler
    index = GPTSimpleVectorIndex(documents, chunk_size_limit=256)
  File "/var/lang/lib/python3.8/site-packages/gpt_index/indices/vector_store/simple.py", line 48, in init
    super().init(
  File "/var/lang/lib/python3.8/site-packages/gpt_index/indices/vector_store/base.py", line 43, in init
    super().init(
  File "/var/lang/lib/python3.8/site-packages/gpt_index/indices/base.py", line 96, in init
    self._index_struct = self.build_index_from_documents(
  File "/var/lang/lib/python3.8/site-packages/gpt_index/token_counter/token_counter.py", line 54, in wrapped_llm_predict
    f_return_val = f(_self, *args, **kwargs)
  File "/var/lang/lib/python3.8/site-packages/gpt_index/indices/base.py", line 231, in build_index_from_documents
    return self._build_index_from_documents(documents, verbose=verbose)
  File "/var/lang/lib/python3.8/site-packages/gpt_index/indices/vector_store/base.py", line 74, in _build_index_from_documents
    self._add_document_to_index(index_struct, d, text_splitter)
  File "/var/lang/lib/python3.8/site-packages/gpt_index/indices/vector_store/simple.py", line 64, in _add_document_to_index
    nodes = self._get_nodes_from_document(document, text_splitter)
  File "/var/lang/lib/python3.8/site-packages/gpt_index/indices/base.py", line 197, in _get_nodes_from_document
    text_chunks = text_splitter.split_text(document.get_text())
  File "/var/lang/lib/python3.8/site-packages/gpt_index/langchain_helpers/text_splitter.py", line 128, in split_text
    cur_num_tokens = max(len(self.tokenizer(splits[start_idx])), 1)
" when parsing large PDF datasheets with small chunk sizes