Thanks but before that, I removed the BP, and created a new one (thankfully it was my first BP so it did not have any data… thankfully…, but I already had set Inputs in the controller, also had the game mode, so I replace it in a few places,
If it happens again I will try.
I think… the probable cause might be: (Probably… can’t confirm) that instead of removing the cube from the mesh details, I might have clicked the cube in the editor viewport and press delete from there, I can’t confirm this now of course, just a noob mistake if that was what happened.