Solved by snehankekre in post #2 
              
              
                Hi @steeley  
I suspect the error is caused by an outdated entry in your config.toml file. Do you have a global config file located at ~/.streamlit/config.toml or a project config file at $CWD/.streamlit/config.toml , where $CWD is the folder you’re running Streamlit from? 
If so, deleting the file …