On what computer operating system is your Premiere Elements 13 running on?
What are you (manually) or the project (automatically) setting as the project preset?
(See Edit Menu/Project Settings/General and the readings for Editing Mode, Timebase, Frame Size,
and Pixel Aspect Ratio (even if fields look grayed out).
What are the properties of these source media, including file extension? The brand/model/settings of the camera that recorded the
video may give us this information.
When the source media hit the Timeline for the first time, is there an orange line over their content? Or is there
no colored line and an orange line appears over them only after you have edited them?
Please elaborate on "poof" after rendering the Timeline content by pressing the Render button above the Timeline content with the orange line over it.
a. Media Offline displays?