Hi everyone,
I have been having the same issue and decided to go online looking for a fix. I found the following link:
This is the only solution that I could find so far. It requires that you remove the twitteR package you currently have installed and download another one from github through the use of the devtools package.
I did just that and used the code provided by the link above and everything works fine for me.
Please follow the blogger and give him a shout-out on Twitter, if you want!
Cheers!
