I'm looking for some diagnostic help with this- I have a strange flare in the middle of this frame. It is the only frame on the roll that has it, and the frame is from the middle of the roll, so it's not an in-camera light leak or the roll leaking.

WeirdFlare.jpg

Camera is a Rolleiflex 2.8E, with a Rolleinar 1 attached. Film is Fuji NPS160.