This is a super noob question, I lost my window in the right. Where in object mode I can add modifiers. Had customised my startup screen with a lot of settings how I like and hope to repair this without going to factory settings, who can help out?
Your bottom right window “Director’s chair” seems to be there. It’s a camera view which is normally focused on the default cube. There is no cube in your scene however, so the camera in the bottom right corner is not looking at anything.