Moving the mouse while collecting files causes AE to skip files/freeze
This is such a weird bug and has existed for a few years, it doesn't affect me much because I don't use "Collect Files" very often, but when I do need to use it I'm baffled at why this exists.
Currently on macOS High Sierra 10.13.3, AE CC 2018 15.1.1, but this bug has existed in prior versions.
When running through the "Collect Files" process, if you even accidentally nudge the mouse while files are copying, AE will either freeze until force-quit, or just skip the file it's currently copying. I've had to unplug the mouse before initiating Collect Files to ensure that it actually copies every file.
Would be nice if this feature could work without such a weird workaround.

Thank you for filing this bug report.
A fix for the problem you describe, that moving the mouse during Collect Files causes the process to fail, was applied in the April 2017 release of After Effect CC (version 14.2).
https://helpx.adobe.com/after-effects/kb/bug-fixes-in-after-effects-april-2017.html
Since that time, your report is the first incident we’ve heard of this problem resurfacing. We need additional information to diagnose the problem.
Can you provide us a screen capture video of the problem in action? Please send a link (no attachments) to aebugs@adobe.com.
A copy of the project file experiencing the problem would also be useful.
Other helpful information:
- How many files are being copied?
- Are these movie files or still image sequences, or both?
- What are the sizes of the files?
- Are the files being copied to or from a network location?
- If a network location is involved, does the problem change if the files are only copied to or from a local drive?
The above questions will help us analyze the problem. We’re looking for conditions that affect the file copy, such as large number of files to copy, or increased copy times due to network connections.