When riding a horse, moving the mouse up or down (consequently causing the camera to move as well) and opening the inventory while the camera/mouse is still moving will cause the camera to continue to move, making the view upside down.
When riding a horse, moving the mouse up or down (consequently causing the camera to move as well) and opening the inventory while the camera/mouse is still moving will cause the camera to continue to move, making the view upside down.
Duplicate of MC-16180, please use the search function to see if your bug has already been submitted. Currently over 55% of tickets are being closed as duplicate.