Apple kills kernel extensions: Dropbox re-architects sync onto File Provider
2019–2022 (macOS 12.3 deadline)
Apple's deprecation of kernel extensions forced Dropbox to rebuild its macOS sync on Apple's File Provider framework; macOS 12.3 (2022) removed the kext support Dropbox's online-only files relied on, changing behavior and temporarily breaking how third-party apps opened online-only files.
What happened
For years, Dropbox's online-only and Smart Sync features on the Mac depended on a kernel extension (kext) that let placeholder files behave like real files to every app on the system. Apple had been deprecating kexts since 2019 in favor of user-space frameworks, granting Dropbox and Microsoft temporary signing exemptions while they re-engineered. With macOS 12.3 (Monterey) in 2022, Apple removed the system support those kexts relied on, and Dropbox had to migrate to Apple's File Provider framework.
The transition changed user- and developer-visible behavior. Apple acknowledged that after updating to macOS 12.3, users could temporarily hit problems opening online-only files in some third-party apps. Under File Provider, the Dropbox folder moved into ~/Library/CloudStorage, so previously linked files in third-party apps had to be relinked; sync performance came under macOS's control (and could throttle on low battery or heat); LAN sync was disabled; macOS package files such as .pages and .numbers began behaving as regular files; and certain libraries (Photos, Final Cut Pro, Adobe InDesign lock files) could no longer sync.
The re-architecture was driven by Apple, not Dropbox, but it forced a fundamental rewrite of Dropbox's most distinctive Mac feature and disrupted the integrations and workflows built around the old behavior.
Impact
The File Provider migration was one of the most disruptive technical changes in Dropbox's history on the Mac, breaking long-standing assumptions for both users and the apps that integrated with the Dropbox folder. It removed capabilities (LAN sync, package-as-folder behavior, certain library types) and handed control of sync timing to the OS, generating sustained user complaints and forcing third-party developers to test and adapt their integrations.