Mac OS X Lion 10.7.3 doesn’t sync Mobile Documents (SOLVED)

Before 10.7.3 the somewhat hidden iCloud Documents folder …

~/Library/Mobile Documents

… was a nice DropBox alternative to keep personal data on several Macs in sync. GoodReader on iOS also used that mechanism to synchronize files between GoodReader installations on different iOS devices and the Mac(s) of the user. The latest Mac OS X update 10.7.3 seems to have broken that feature. The folder on the Mac remains empty.

Update 14.02.2011: It looks like Apple has solved the problem. Sync is working again for me.

Update 21.02.2011: If you read the comments you’ll see the problem is not really solved. What can be said so far is that the sync problems are rather related to a bug in Mac OS X 10.7.3 than Apple wanting to keep us from using this nice DropBox-like feature. Workaround after the break…

ubd, the ubiquity daemon, is the software part in Lion to keep the Mobile Documents folder synchronized with iCloud. It resides hidden in …


The interesting observation about ubd is that Mobile Documents-syncing works immediately again if you launch that daemon on the command line (Terminal), though the man-Page for ubd states “users should not run ubd manually“… πŸ˜‰


Open the Terminal (Applications -> Utilities) and type or copy and paste:

Β while true; do /System/Library/PrivateFrameworks/Ubiquity.framework/Versions/A/Support/ubd; done

… and press enter. As long as the Terminal remains open this should keep Mobile Documents-sync working.

17 thoughts on “Mac OS X Lion 10.7.3 doesn’t sync Mobile Documents (SOLVED)

  1. Whyyyyy, Apple, whyy? Goodreader is still syncing files between my iPad and iPhone with iCloud but none of this is reflected in the Mobile Documents folder on my Mac, and dragging and dropping files into that folder will no longer make them appear in Goodreader on my iDevices. I wonder what kinds of changes Apple made to cause this odd behavior?

  2. I see exactly the same behavior and am quite sad about it: I used the synchronized folder to store documents I need at the university and never had to care about forgotten documents anymore.
    Hopefully Apple considers this 10.7.3 behavior as a bug and not a feature (less traffic for their servers).

  3. It’s not working for me. I’m not getting a sync either between iMacs or with GoodReader on my iOS devices. Anyone have any ideas?

  4. It’s quite strange: The syncing does work for me – somehow, or rather: sometimes. When I change something in GoodReader on one iOS device the changes appear on another iOS device within seconds (if I restart GoodReader). However, it takes somewhere between minutes and hours for the changes to be pushed to the Mac (and vice versa).
    So far I was unable to find any reason / influencing factor for the time it takes to get in sync again.

    iCloud: It’s like magic – you never know when or if it works. πŸ™

    Update: Please read the updated post: There is a workaround. πŸ˜€ Please let me know if it works for you.

  5. Workaround seems to be great. I’m not sure if I’ll trust my files to the Mobile Documents folder anymore, though, if Apple won’t support it.

    Is anyone running the Mountain Lion preview? I wonder if the functionality is fixed there?

  6. Turns out there is a much simpler way – and quite a obvious one:

    If you run an app on the Mac which uses iCloud, then the OS will start the synchronization process itself. The first free app with iCloud support I found in the App Store was Memo – Sticky notes.
    Just run the app and synchronization should begin. πŸ™‚

  7. I installed the free memo-sticky notes,
    started it
    ubd appears in the task monitor

    and uploading of documents in the goodreader folder begins…

    Thanks a lot

  8. Hi,
    I have the same problem with iCloud not syncing Mobile Documents anymore after 10.7.3.

    I have noticed that /System/Library/LaunchAgents/ was updated after 10.7.3 and ubd is now configured with KeepAlive=false (was true, prior to 10.7.3) and RunAtLoad=false (was true).

    Unless some application like iA Writer is fired up, ubd seems to never start by itself (I waited for 1hr after boot, to no avail); when iA Writer fires up, udb will as well and synchronization will start for all documents in Mobile Documents (including the ones withing the GoodReader container).

    I have also noticed that if I close iA Writer, udb will shutdown after around 24minutes to never be run again (unless another iCloud-aware application is run).

    As a side note: Day One (for Mac) 1.5 is having problems on my side. Unless I visit the Preferences panel, udb is not run and no sync happens. Among the iCloud-aware applications I have, iA Writer seems the most consistent in its interation with ubd.

    I will keep digging into this and I truly hope that ubd will revert back to the old behavior with 10.7.4!


  9. Hi,

    Thanks for the help with the Memo-sticky solution. It works great and it’s nice to have the functionality back.

    That said, I kind of don’t like having a random app lurking in the background like this.

    Would it be possible to just turn on the proper parameters with a login script (“hook” as Apple calls them) instead? I’m not skilled enough to know or even try it by myself.


  10. Hello,

    I’ve used Automator to create a shell script:
    /System/Library/PrivateFrameworks/Ubiquity.framework/Versions/A/Support/ubd &
    The attached ampersand tells the process to fork. So the script quits immediately after start and the deamon continue to run.
    I saved the script in Automator as a program and use it as a logon object.

  11. Brilliant comments!! There’s tons of forum posts on this on the web, but this thread was useful in all accounts.

    I began this whole mess on 10.7.3 when I noticed there was no MobileDocuments folder on my IMac (@work). However on my MBA (@home), also 1o.7.3, the folder was there.

    These are my failed attempts:

    1)Tried to disable on/off with and without restart in between.
    2)Installed iWorks
    3)Manually created the folder
    Meanwhile drag and dropping documents on Web Module of IWorks, caused IWorks unexpected error in Chrome, in Safari, dragging and dropping did nothing.
    4)Installed Keynote on my IPhone, allowed me to drag and drop files from my IMac.

    Found this page, downloaded Memo from App store. First init, the Memo App was frozen. When I opened the Library folder, found MobileDocuments with its respective Application Sub-Folders.

    Created a new shell-script per Ronny’s suggestion and added it to my startup profile.
    I now have fully working iCloud sync again.

    THANKS all!

  12. Sync works fine with Ronny’s shell script started manually. But script won’t work when added to the startup profiles of my macs. Any idea someone?
    Thanks in advance for any hint.

  13. Much better, safer and easier for most documents: you can open many documents with preview instead of the usual app (right click or option click the file in finder to do so). Then simply choose move to in the preview file menu. This moves the file to the preview folder in mobile documents so you can find it and open it from iCloud with preview on any synchronised mac, or by delving into the preview documents folder withing the mobile folder you can open it directly with an app of your choice.

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