If you look at the article linked below, it will explain that the SlingPlayer for iPad is not compatible with your Slingbox PRO Legacy unit. While it may have worked in the past, it was technically never designed to work on iPad. Therefore, the only way you may get it to work again would be to install an older version of SlingPlayer for iPad. However, we cannot guarantee that it will work.
I apologize for the inconvenience.
Sling Media Forum Moderation Team