macOS 26.1 – Severe lag in Open/Save panels when iCloud Drive root contains any items (FileProvider v3 regression)

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I’ve filed this as FB20943098 (macOS 26.1 – FileProvider v3 synchronous enumeration bug), but posting here in case others can reproduce and add duplicates.

Systems:

macOS 26.1 (26B82)
M4 Mac mini Pro and M4 MacBook Air

Symptoms: In any app (TextEdit, Pages, Browsers, etc.), the Open/Save dialog lags for ~1s per folder navigation click. CPU spikes from fileproviderd, cloudd, bird, and siriactionsd.

Key discovery:

If my iCloud Drive root is empty (only “Documents” and “Downloads”), performance is perfect.
As soon as any folder or file exists at the root of iCloud Drive, the lag returns immediately.
Moving those items into “Documents” or “Downloads” makes everything smooth again.

Analysis: Based on process traces and container paths, this appears to originate in the FileProvider.framework subsystem (via fileproviderd), which mediates iCloud Drive. Early evidence suggests that folder enumeration of the iCloud Drive container root may be blocking UI threads in macOS 26.1. I believe this may be related to the recent internal migration of the file-provider backend (often referred to as “v3”), but I do not have direct confirmation from Apple of that exact change.

MacOS 26.1’s new FileProvider v3 backend seems to be blocking the Open/Save panel while enumerating the iCloud Drive root container (~/Library/Application Support/FileProvider/723EBBFF-…).
Folder enumeration seems to wait synchronously for metadata from fileproviderd, and if the local SQLite DB is busy (WAL writes or sync state checks), UI freezes briefly.

Workarounds:

Disabling iCloud Drive entirely fixes the issue.
Simply disabling Desktop/Documents sync does not help.
Keeping the iCloud Drive root empty avoids the lag without turning iCloud off.
I am able to store whatever I please in the Desktop or Documents folder which is currently syncing.

Would appreciate if others on 26.1 could confirm.

Engineers: I’ve attached fs_usage, log stream, and process samples to my Feedback ticket via the FB20943098.

Expected behavior: Folder enumeration in NSOpenPanel should remain asynchronous regardless of FileProvider background activity. Open/save modal should be responsive and smooth.

Answered by DTS Engineer in 865479022

I’ve filed this as FB20943098 (macOS 26.1 – FileProvider v3 synchronous enumeration bug), but posting here in case others can reproduce and add duplicates.

This is a known issue (r.161915582). While it isn't fixed in the current seed (macOS 26.2 25C5031i), the issue is a high priority that's being actively investigated.

__
Kevin Elliott
DTS Engineer, CoreOS/Hardware

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Answer 1

DTS Engineer OP

Apple

1d

Accepted Answer

I’ve filed this as FB20943098 (macOS 26.1 – FileProvider v3 synchronous enumeration bug), but posting here in case others can reproduce and add duplicates.

This is a known issue (r.161915582). While it isn't fixed in the current seed (macOS 26.2 25C5031i), the issue is a high priority that's being actively investigated.

__
Kevin Elliott
DTS Engineer, CoreOS/Hardware

1

Answer 2

rappabrad OP

10h

Awesome. I don't know if this will help, but I seem to have resolved the problem on my M4Pro Mini running these two commands:

# Quit apps that might use iCloud Drive
osascript -e 'tell application "Finder" to quit'

# Kill iCloud daemons
killall bird cloudd fileproviderd

# Remove local iCloud metadata cache (NOT your files)
rm -rf ~/Library/Application\ Support/CloudDocs
rm -rf ~/Library/Caches/CloudKit
rm -rf ~/Library/Caches/com.apple.CloudDocs
rm -rf ~/Library/Preferences/MobileMeAccounts.plist

# Restart the system
sudo shutdown -r now

and this one:

osascript -e 'tell application "Finder" to quit'
killall fileproviderd bird cloudd

# Move the offending FileProvider container aside
mv ~/Library/Application\ Support/FileProvider/723EBBFF-303E-471D-924D-C7D140F50B49 \
   ~/Library/Application\ Support/FileProvider/723EBBFF-303E-471D-924D-C7D140F50B49.old

# Let macOS rebuild a fresh one on reboot
sudo shutdown -r now

The strange thing is, my Macbook Air the same commands didn't do anything. There were two instances where I resolved the lag on my Air.

I removed a specific folder from the ROOT directory of my iCloud drive. Unfortunately the problem came back
I then took everything out of my drive (including desktop and documents), made a backup of it. Then screen shared into my M4 Mini and from that backup, restored it to documents on my Mini. Even after the Air was done syncing, it was perfect for a little bit.
Macbook Air, I deleted everything. Lag. Turned OFF desktop/documents. Lag.

I hope this MAYBE helps.

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