First, ensure that your new Player Controller is correctly set in the GameMode settings under the “Default Classes” section. Next, verify that your Player Pawn (or Character) is still assigned in the GameMode; if it’s missing or set to null, your player won’t appear in the game. Additionally, check the Level Blueprint to make sure you’re not accidentally destroying or hiding your player pawn at runtime. Lastly, confirm that the player pawn’s spawn location is valid and that it has been set to auto-possess by the Player Controller in its settings. If all else fails, try restarting the editor, as sometimes changes may not fully register until a restart.