[2018] I saw this on Epic's forums and feel that this deserves a bit more attention. A user has a modified controller because they have a disability, and unfortunately that is causing the game to kick them. Per the forum poster:

Hi,

I have a very big problem and the support does not answer me. Since a few days I am disconnected from each game of fortnite. Disconnection and this message "the selected device does not match, please disconnect the mouse or keyboard and restart fortnite" I did everything, restart the console, clear the cache, reinstall the game but nothing helps, I still have the same problem. I am on xboxone. How to do ? I understand that epic games wanted to chase gamers out of order, but my controller was simply changed by the amputation of my right arm last June to following a cancer. I play with a controller adapted to my handicap, the keys are all deported to the left. I can't play a full game. HELP ME PLEASE

Here is the original post on Epics forums: https://www.epicgames.com/fortnite/forums/battle-royale/royale-with-cheese/767083-my-handicap-is-a-problem-for-epic