CfExecute(TRANSFER_PLACEHOLDERS) returns E_INVALIDARG inside an FSLogix profile container
A Cloud Files sync provider encounters issues when its sync root is redirected by FSLogix to a per-user VHDX container. Specifically, CfExecute calls to transfer placeholders fail with E_INVALIDARG for certain FETCH_PLACEHOLDERS callbacks. These callbacks are triggered by name lookups of non-existent children within placeholder directories that have on-demand population enabled and have not been accessed recently. Directory enumeration callbacks, however, are handled correctly.This problem can be reproduced on clean Windows Server 2022 and 2025 installations with FSLogix profile containers. The issue does not occur when the sync root is not within an FSLogix-redirected profile, such as on a plain VHDX volume or a mount point, or on Windows 11. Different OS patch levels and FSLogix releases have not affected the reproducibility of this bug.Workarounds include opening the directory with FILE_LIST_DIRECTORY before answering the callback or disabling on-demand population for the directory using CfUpdatePlaceholder. The provider currently uses the directory open workaround. The developers are seeking confirmation if this is a known issue with Cloud Files sync roots in FSLogix-redirected profiles. They have provided a PowerShell script and logs to demonstrate the problem on a public repository. Further details and environment matrix information are available on Microsoft Q&A.
CfExecutecalls to transfer placeholders fail withE_INVALIDARGfor certainFETCH_PLACEHOLDERScallbacks. These callbacks are triggered by name lookups of non-existent children within placeholder directories that have on-demand population enabled and have not been accessed recently. Directory enumeration callbacks, however, are handled correctly.This problem can be reproduced on clean Windows Server 2022 and 2025 installations with FSLogix profile containers. The issue does not occur when the sync root is not within an FSLogix-redirected profile, such as on a plain VHDX volume or a mount point, or on Windows 11. Different OS patch levels and FSLogix releases have not affected the reproducibility of this bug.Workarounds include opening the directory withFILE_LIST_DIRECTORYbefore answering the callback or disabling on-demand population for the directory usingCfUpdatePlaceholder. The provider currently uses the directory open workaround. The developers are seeking confirmation if this is a known issue with Cloud Files sync roots in FSLogix-redirected profiles. They have provided a PowerShell script and logs to demonstrate the problem on a public repository. Further details and environment matrix information are available on Microsoft Q&A.