Rename Files in FTP with R using Rcurl

I am trying to rename an ftp file from R with this:

RCurl::curlPerform(url =paste0(ftp,"Folder/"), 
        quote= paste0("RNFR ", file, " RNTO ", newfile), 
        userpwd = "anonymous:anonymous")

and I get the following error message: Error in function (type, msg, asError = TRUE) : QUOT command failed with 550

I know that error is usually due to a command requiring access to a file that does not exist or that the user does not have access rights to, but the strange thing is that i can write a new file in the same folder with ftpUpload, so i think it's not a permission issue.

Thanks