Does the error message look like this: “An HTTP error 0 occurred. /node_images/js”?
There are limitations on the size and type of photographs that can be uploaded. It is likely your photograph is too big. It must be less than 500kb (0.5mb) in file size and no larger than 1024x768 pixels. Photographs can be resized using editing software such as Microsoft Office Picture Manager and Photoshop, or free downloads such as Google’s Picasa.
Yes, please upload at least one image. Research has shown that guides that are illustrated are more popular - and visited more - than those without. Pictures add colour and life to your piece. Most writers choose to add at least six images, some upload more than twenty. See the other image FAQs if you have any problems with this.