Case 3 has occurred. I checked that "Show Remote" is enabled, I tried to rerun Setup Video Sources. None of that worked. I called Sling Support, they had me reset the Slingbox. I am not able to find any manufacturers or models in the search box. It hangs when tried to search.
3, My On-Screen Remote has suddenly disappeared.
First make sure you have actually selected ‘Show Remote’ on the web-based player, and/or tapped on the Remote icon on Slingplayer.
If that option is greyed out then rerun the ‘Setup Video Sources’ to refresh the details in the Slingbox in case they have been corrupted.
If you do not get a list of manufacturers showing up, or you get a message along the lines of ‘This Slingbox was not designed for use in ..<your country>’ and this happens regardless of country then your box has probably failed and you need to contact Sling Support.