Error for Transfer Failed


I'm a total newbie to web-design. my friend built my website, but he takes a year to update when I almost need to update weekly. So I designed a new site. I have the index.html made w/ the content. He has a folder where the website is called "public_html". I made a new folder and dragged all the files into the new folder.

I then checked my site and it was down. So I knew that this was where the live files were.

Here in lies my problem; I want to add my new files. index.html/and other files, but it will NOT transfer over. I get this this exact error "Transfer failed. Use the Transfer Queue for automatic retries".

Does anyone know why it isn't letting me add my new files?

Thank you so much