Seems to work fine on my end. I was using an android Galaxy S3. Try checking the file size of the image or format of the image you are trying to upload. When uploading the above attached image, I clicked on the camera icon and selected "camera", then took the picture, "save", then post to "this forum"
For what it's worth, I'm using the iphone app. I've uploaded dozens of images before without issues. I've tested with saved images, "live" images, and even images that I had uploaded here successfully in the past.