It is much easier to upload images and PDF files into the WCMS by using drag-and-drop uploading. Remember though, that the name of your file will be the same name that is used in the WCMS, so always use the correct file name extension (for example, .jpg or .gif or .png for images, and .pdf for PDF files).
If you are uploading an image file, open the assets folder and then select the images folder.
If you are uploading a PDF file, open the assets folder and then select the pdf folder.
Click on "New" in the top menu bar, and select File
When you see the "New File" dialog, drag the file from your computer into the drop region labeled, "Drop file here to upload" (See the screen shots below.)
Click the Submit button