April 2018 After Effects loses PNG sequences
This is a bug report (although this web site makes it infuriatingly unclear if this is where bug reports go).
I am seeing behavior in the new version in which projects that contain PNG sequences seem to lose those sequences, giving a cant open dialog for every g..d... piece of media. I can cause the error by simply tabbing to another app and then back into AE. Note that projects open fine with all media and if you dismiss these multiple warning dialogs, everything works fine (of course for some projects, that can be hundreds of dialogs).The error seems to disappear if you turn off Auto Footage Reload (hey, who needs features anyway?).
Windows 10 Fall Creators Up to date 256GB Ram All SSD or m.2 Nvida 2 Titan X Pascals 2 1080's.