Non-character argument in R

Question

While using twitteR package for R, I am getting the following error

Error in strsplit(response, "&") : non-character argument twitter

when trying to send my oauth credentials using this code

cred <- OAuthFactory$new(consumerKey=consumerKey, consumerSecret=consumerSecret,
                         requestURL=reqURL, accessURL=accessURL, authURL=authURL)

cred$handshake(cainfo=system.file("CurlSSL", "cacert.pem", package="RCurl"))

If I use http instead of https, I am geting an error

Error: Forbidden

I am working on a Windows machine.