[quote='901315022, DTS Engineer, /thread/841771?answerId=901315022#901315022'] Why? What are you actually trying to do here? Setting the specific issue aside, I’m not sure what the consequences of taking over that folder might be, but I’m not surprised that it failed. [/quote] The intention is to use both frameworks in tandem to take advantage of what each offers: namely, the file synchronisation provided by FileProvider and the fine-grained hooking of file system operations provided by FSKit. It would also be useful to display a custom UI on a long press using the FileProvider UI framework, which, as far as I know, is the only way to do this. [quote='901315022, DTS Engineer, /thread/841771?answerId=901315022#901315022'] This actually has me a bit confused. What were the actual circumstances involved here? ACLs aren’t actually stored as xattr’s (at least not by the system itself) and, if they were, then I’d expect FSKit to block requests from ever reaching your file system. [/quote] When I wrote the original post, I was referring to the now-deprecated setAttributes call , not to xattrs. Given the limitation raised in my first message, the remaining option is to build a custom file synchronisation workflow with FSKit to support a network file system. I still believe it’s reasonable to expect these two technologies to be interoperable. My concern is that an enhancement request for Access Control List support in FSKit would only address the first of many blockers to getting the two frameworks to work together. I still intend to raise an enhancement, but first wanted to see whether you had any further input on the points above.