If you don't mind, I found this helpful to some people having trouble uploading pictures.
Here's what I find works for me:
1. Go to an uploader site (my favorite to use is: Tiny Pic it's super easy)
2. Upload your picture per site's instructions. (if using Tiny Pic, I find it helpful to change the size to "Thumbnail" or "Website/Email" using the Resize button)
https://i51.tinypic.com/2nlck1f.jpg
3. Then you should come across an option for the code. Choose BBCODE, or IMG code. Not HTML, not URL. Otherwise it will not work. It should have these things [ ] and start with [IMG ]
https://i51.tinypic.com/2mepe0z.jpg
4. Copy this code and paste it right into the thread! Easy as that!