A change in the API is causing problems for unofficial apps.
Instagram Blocking Photos from Third-party Applications : Read more
Instagram Blocking Photos from Third-party Applications : Read more
According to the Verge, users of popular Instagram for Windows Phone app 'Instance' are seeing their photos deleted soon after they are uploaded to Instagram. Instance developer Daniel Gary confirmed to the Verge that Instagram seemed to be "detecting when photos are not uploading via the official app" and removing them. Instagram has since told the Verge that the issue is down to a change in the Instagram API.