Kinda new. When I import a png sequence of an outlined subject (meaning the area around the subject is clear) AE is adding black rectangles against the subject that cover the edges of the subject. See pic. Do I need to set another mask inside AE? Is there a new setting in Photoshop 6, where I made the pngs so that I have to do something to make sure there's an alpha channel?
Depends on how you saved the PNG in PS. There's a difference using Save As... and Save for Web... and of course for video editing only 24bit PNGs make sense at all... Also check your footage interpretation. Anyway, simply use native PSDs or TIFFs if you'already work in PS. Much less troublesome then the many tiny annoyances with PNGs.
This is what a PNG looks like when the alpha channel doesn't come through or is being ignored.
In After Effects, are you able to change the way the alpha is applied in interpret footage? If not, then the alpha is likely missing.