Bug / Feature : eature Request: Support for Legacy Dropbox Sync (or stop caching 0-byte placeholder files as corrupt)

The Problem: Currently, when After Effects attempts to read a media file that is marked as "online-only" via Dropbox's legacy sync mode, it errors out. Instead of triggering a download, AE reads the raw 0-byte placeholder file, fails, and throws a "Media Offline" or bad header error.

To make matters worse, AE then permanently caches this 0-byte state in the Common Media Cache. Even if we go into Finder, right-click the file, and select "Make Available Offline," AE will still refuse to read the newly downloaded physical file until we manually navigate to ~/Library/Application Support/Adobe/Common/Media Cache Files and trash the cache. I build a custom bash command to handle this situation which mitigates a bit but still hard to explain to the whole team every time this happens or to freelancers. 

Why "Just update to macOS FileProvider" isn't an option: The standard response from Adobe support is usually to ensure we are using the modern macOS File Provider API for cloud sync. However, Dropbox and Apple have a hard eligibility limit: if your Dropbox account contains over 500,000 files, you cannot use the File Provider architecture and are permanently stuck on Dropbox's legacy sync mode.

For any larger team / workflow managing complex asset libraries, hitting a 500,000 file count happens incredibly fast. Large teams literally cannot migrate to the new OS-level sync, meaning we are trapped with this legacy behavior and broken offline-media workflows.

Should we be using dropbox for this? Probably not, but thats not a decision that is easy to unwind with TBs of data up on dropbox. It’s actually worked shockingly well for what it is, and has enabled most of us to keep a hybrid WFH setup where we can just sync what we need. 

The Ask:

1. Stop caching 0-byte read failures. If AE encounters a 0-byte file or missing header upon initial import or project load, please do not write that failure to the Media Cache. If we manually force the download in Finder, AE should immediately recognize the physical file on the next read attempt without requiring a destructive cache purge.

2. Recognize macOS Extended Attributes. If a file returns 0 bytes via standard read operations, ideally AE could check for the hidden extended metadata tags (xattr) that cloud providers use to flag placeholders. Instead of throwing a generic corruption error, AE could simply prompt: "Offline cloud file detected: Please download via Finder to proceed."

We are in an awkward situation where our chosen file host Dropbox, Apple, and Adobe are not playing nicely anymore, when it worked perfectly pre 2022. We would massively appreciate any workflow relief here.

Disclaimer: Some of this I researched with Gemini Ai and I had it help me form some of this feature request, but these are 100% real problems I’m having and the info is valid.