Question: I have been working through a LangChain tutorial and have hit this problem when trying to import langchain into python in vscode on macos 13.4.1. from dotenv import load_dotenv import os import streamlit as st from PyPDF2 import PdfReader from langchain.text_splitter import CharacterTextSplitter def main(): load_dotenv() # print(os.getenv("OPENAI_API_KEY")) st.set_page_config(page_title="Select the Data PDF") st.header("Load your PDF below: ⚡︎") pdf = st.file_uploader("Upload your PDF", type="pdf") if pdf is not None: pdf_reader = PdfReader(pdf) # the PdfReader reads in chunks of one page each text = "" for page in pdf_reader.pages: text += page.extract_text() st.write(text) # split text into chunks (inside outer if not None) # the CharacterTextSplitter class has properties that need to be set... # so pass in property parameters to the class inititializer text_splitter = CharacterTextSplitter( separator="\n", chunk_size=1000, chunk_overlap=200, length_function=len #python's basic length function ) chunks = text_splitter.split_text(text) st.write(chunks) if __name__ == '__main__' : main()  I see a suggested fix, but I do not understand how to implement it. I get the following error on the Stringlit web page and the VSCode terminal: PydanticUserError: If you use `@root_validator` with pre=False (the default) you MUST specify `skip_on_failure=True`. Note that `@root_validator` is deprecated and should be replaced with `@model_validator`. For further information visit https://errors.pydantic.dev/2.0/u/root-validator-pre-skip Traceback: File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 552, in _run_script exec(code, module.__dict__) File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/app.py", line 6, in <module> from langchain.embeddings import ImportError File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/langchain/__init__.py", line 8, in <module> from langchain.agents import MRKLChain, ReActChain, SelfAskWithSearchChain File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/langchain/agents/__init__.py", line 2, in <module> from langchain.agents.agent import Agent File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/langchain/agents/agent.py", line 11, in <module> from langchain.chains.llm import LLMChain File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/langchain/chains/__init__.py", line 2, in <module> from langchain.chains.conversation.base import ConversationChain File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/langchain/chains/conversation/base.py", line 7, in <module> from langchain.chains.conversation.memory import ConversationBufferMemory File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/langchain/chains/conversation/memory.py", line 7, in <module> from langchain.chains.conversation.prompt import SUMMARY_PROMPT File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/langchain/chains/conversation/prompt.py", line 2, in <module> from langchain.prompts.prompt import PromptTemplate File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/langchain/prompts/__init__.py", line 2, in <module> from langchain.prompts.base import BasePromptTemplate File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/langchain/prompts/base.py", line 35, in <module> class BasePromptTemplate(BaseModel, ABC): File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/langchain/prompts/base.py", line 41, in BasePromptTemplate @root_validator() File "/Users/jamesallison/Desktop/Python Apps Temp/LangchainPDF/.venv/lib/python3.8/site-packages/pydantic/deprecated/class_validators.py", line 228, in root_validator raise PydanticUserError( 

Answer: I was using LangChain 0.0.20 and I got the same issue. Upgrading to Python 3.9 and LangChain 0.0.224 fixed this issue for me.