Game thinks my controller is being used by another player

[Augus]

Using a wired Gamecube controller for the Switch. Controller works fine for SRB2Kart, but SRB2 proper refuses to let me use it.

 

[Zwip-Zwap Zapony]

If you want player 1 to use that as an input device, set player 2's gamepad option to "None", or vice-versa if you want it the other way around.

Alternatively, use the console to set "use_gamepad2" to 0, and then set "use_gamepad" to 1, to accomplish the same thing.

 

[SonktheHonk]

i have the same problem and player 2 isn't even using the controller

 

[PlatterTheFinch]

This message appears when the controller is not supported in the SDL2 input layer. Really all you can do is update SDL2 and hope for the best.