I don't see those criticals here; could you run Nautilus inside a gdb session with the environment variable G_DEBUG set to "fatal_criticals" and paste a backtrace of what's happening? I believe those criticals come from an extension.

Michael, were you able to collect trace as requested in comment#1 ?

Closing this bug report as no further information has been provided. Please feel free to reopen this bug if you can provide the information asked for.
Thanks!

I still get a similar message appended every few seconds, the line number is different though:

(nautilus:2265): GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed

I tried the following to collect the requested information:

> env G_DEBUG="fatal_criticals" gdb nautilus

However, it does not even seem to start nautilus. Could anyone tell how the information can be collected? I use ubuntu linux.

I installed the development version and typed 'run'in the gdb console. I got the following output. I hope it helps.

--------------------------------------------------------
Starting program: /usr/bin/nautilus 
[Thread debugging using libthread_db enabled]
[New Thread 0x7fffec6ce700 (LWP 8155)]
[New Thread 0x7fffebecd700 (LWP 8156)]
[New Thread 0x7fffeb6cc700 (LWP 8157)]
Initializing nautilus-gdu extension
[New Thread 0x7fffdcf2e700 (LWP 8158)]
[New Thread 0x7fffdc72d700 (LWP 8159)]
[New Thread 0x7fffdbf2c700 (LWP 8160)]
[New Thread 0x7fffda108700 (LWP 8163)]
[New Thread 0x7fffd9907700 (LWP 8164)]
[New Thread 0x7fffd9106700 (LWP 8165)]

GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed

Program received signal SIGTRAP, Trace/breakpoint trap.
0x00007ffff4445313 in g_logv () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
--------------------------------------------------------

(In reply to comment #5)
> 
> GLib-GObject-CRITICAL **: g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT
> (value)' failed
> 
> Program received signal SIGTRAP, Trace/breakpoint trap.
> 0x00007ffff4445313 in g_logv () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
> --------------------------------------------------------

We need a backtrace for this crash. When this happens in gdb, type "bt" in the console, and paste the output you get.
You might need to install glib/gtk+/nautilus debug info packages for your distribution to get a good trace. See also https://live.gnome.org/GettingTraces

I get the following stacktrace:

+ Trace 229904

#3 ??
from /usr/lib/libdbusmenu-gtk3.so.4

This is apparently caused by an Ubuntu-specific component => NOTGNOME.
Please report this bug in Launchpad.