After Effects users are encouraged NOT to get the Quicktime 7.4 Software Update for Mac. After users update to QT7.4, renders in AE report the following error: “you do not have permissions to open this file (-54) (44::53).” I have not read if this also affects PC AE users. There is a lot of discussion on this issue at the Apple Support Forums, also some links to external AE forums from there. So this is just a quick reminder to tread carefully with updates if you have a rock-solid system.

UPDATE FROM KENDAL:
I recently had to downgrade QT to 7.3 to get AE CS3 to run correctly. When I downgraded everything ran fine, on 7.4 AE crashed on launch every time. Downgrading is a major pitb. Wish Matt had posted this a few days earlier :(

Update #2:
Mike Curtis is all over this as well, and mentions some issues with DRM or permissions that limits playback of movies you created, spotty reports of Sorensen conflicts, and even an Adobe engineer that mentions issues with Premiere Pro. There’s also the workaround if you’ve already hosed your After Effects install with the 7.4 update (read Mike’s post comments).

Update #3:
Kendal located a very detailed tutorial on how to revert from Quicktime 7.4 if you’ve inadvertently hosed your system with the update. Excellent info.