this means the window is blank
i am doing a slide show so i am using all photos
one window has a photo
then the next window has a blank
the third widow has a photo
the blank sometime diaPPears if one right clicks but not always
In the Timeline, if one has a JPEG, or PNG, or PSD Still Image file, and it is blank, it is usually because the Still Image is too large, and needs to be Scaled down to match the Frame Size of the Project.
Good luck, and hope that helps,
Retrieving data ...