assertion failure: g_bus_unwatch_name: assertion `watcher_id > 0' failed

BTW: I tried to open nautilus in root mode in the terminal which worked.

Faced exactly same problem. Triaging.

Probably a rebuild of Nautilus will help?

I'll try to fix this.

Confirmed. Only a reboot is required

Err, I meant a rebuild, not a reboot.

This is a no-change rebuild debdiff with a neat changelog message. I request you to sponsor this (though there is no point in having a debdiff for a no-change rebuild)

Un-assigning myself since I need sponsorship

I rebuilt the package without any changes on my EC2 instance, and tested the debs locally and nautilus worked!

Anyone facing this bug and running 32-bit Ubuntu can download the rebuilt debs from:
http://people.ubuntu.com/~bilalakhtar/nautilus-bugfix/

I think only the package nautilus needs to be updated, but these were the packages I updated:
nautilus
nautilus-data
libnautilus-extension1

64-bit users: The nautilus rebuilds are still awaiting in the queue on my PPA (ppa:bilalakhtar/bugfixes). Around 5 hours after this comment, you can get the rebuilt nautilus packages from that PPA and install those.

Hopefully this should fix this bug until someone sponsors my debdiff.

This bug was fixed in the package nautilus - 1:2.32.2.1-0ubuntu7

---------------
nautilus (1:2.32.2.1-0ubuntu7) natty; urgency=low

  * No-change rebuild against latest GIO libraries to fix crash on startup.
    (LP: #724285)
 -- Bilal Akhtar <email address hidden> Thu, 24 Feb 2011 21:58:08 +0300

there was no gio change could you explain why it needs a rebuild? there was also changes in the vcs you ignored when you did your upload, you didn't update the vcs either, that's broken...

Hi seb,
      I don't know very well about what exactly was the change (X and Linux were updated, and possibly some other build-deps of Nautilus) but as you can see in the above comments, I manually rebuilt the package and tested it to confirm that the bug would be fixed by a rebuild.

Ubuntu-desktop developers on IRC pointed out that there were some uncommitted changes in the VCS. So, I didn't bother them and left the bug like this. Firstly, a no-change rebuild is nothing but a changelog version bump, and you can easily merge this back in the VCS. Second, I never knew this debdiff would get sponsored so quickly (usually I have to poke sponsors to get things sponsored)

I am sorry if I caused some extra work, but this bug was of 'Critical' importance to me as it rendered Nautilus useless for a large number of Natty users.

This bug _was_ fixed with nautilus version 2.32.2.1-0ubuntu7, but it re-occurred after an update to 2.32.2.1-0ubuntu8...

Not sure why it crashes but the 'g_bus_unwatch_name: assertion `watcher_id > 0' errors are due to 17_disable_locked_automounting.patch

bug #733061 is likely the same issue

bug #732114 seems similar as well

Stack trace: http://paste.ubuntu.com/580133/

Only think I need to do is try and close a nautilus window by clicking on the close button in the titlebar.

I fixed this upstream in http://git.gnome.org/browse/nautilus/commit/?h=gnome-2-32&id=9142d259dcaa6b011604cbd560b94ce31d314b88

This bug was fixed in the package nautilus - 1:2.32.2.1-0ubuntu9

---------------
nautilus (1:2.32.2.1-0ubuntu9) natty; urgency=low

  * 17_disable_locked_automounting.patch: Fix g_bus_unwatch_name() assertion
    failure. (Also committed upstream in 9142d259). (LP: #724285)
 -- Martin Pitt <email address hidden> Tue, 15 Mar 2011 15:12:52 +0100

@Neil J. Patel
The Nautilus crash when clicking the close button is due to one of the overlay-scrollbar packages. Don't know which one but running without those overlay-scrollbar packages works. So it seems to be an inconsistency in the implementation of the scroll button in the Nautilus window and probably a Nautilus issue.

I'm running the latest Natty version and i still have this bug. I can not launch nautilus, it always show message in terminal:

(nautilus:8569): Unique-DBus-WARNING **: Error while sending message: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

Hi, I'm not sure it's the same bug, but with version 2.32.2.1-0ubuntu13 in xsession-errors file, errors are generated continuously.
I attach a video that explains what I mean.

(Natty beta 2 x86_64)

@Benjamim Gois
I had the same nautilus error as you (which seems different from the subject of this bug report). In my case the UbuntuOne client was screwing up DBus somehow. Removing the client immediately fixed the problem:

sudo apt-get remove ubuntuone-client