I'm getting the same thing, Arch Linux (not latest, a couple weeks out of date probably).

Just did a clean install on ubuntu 17.10 getting the same.

I'm getting this error while trying to open Rocket League, doesn't happen in other games like Dota or The Talos Principle.

I'm getting it while running any Source game (TF2, CS:GO, Insurgency)

This also appears when a notification pops up. Animation of the notification stutters since last update.

On some machines I've had problems that printing a large about of text to the console slowed things down; might be the same thing as @kiroma

Same issue in Fedora 26 when starting Rocket League, since the last Steam update.

D-Bus not built with -rdynamic so unable to print a backtrace
process 5337: arguments to dbus_connection_ref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2656.

The same issue in openSUSE Leap 42.2 - terminal is flooded with two types of outputs:

• with "line 2656":

process 4778: arguments to dbus_connection_ref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2656.
This is normally a bug in some application using the D-Bus library.

• and with "line 2794"

process 4778: arguments to dbus_connection_unref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2794.
This is normally a bug in some application using the D-Bus library.

Anyone knows a way to pass this issue? in my case Rocket League doesn't open and it's been week now, I'm starting to get bored. Thanks.

That solved to problem, the game starts normally, thanks!.
The output in the terminal is the same though:

process 29469: arguments to dbus_connection_unref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2794. This is normally a bug in some application using the D-Bus library.

Thank you.

I installed primus-libs-ia32:i386 and primus-libs:i386 in my Debain Sid and the problem was solved!
https://packages.debian.org/sid/primus-libs-ia32

Interesting, I'm not using Bumble at all although this is an Optimus system, I just force Nvidia always on though.

Looks like STEAM_RUNTIME_PREFER_HOST_LIBRARIES=1 alleviates the problem.

Looks like STEAM_RUNTIME_PREFER_HOST_LIBRARIES=1 alleviates the problem.

Didn't work for me. (Arch Linux)

have you installed steam-native on arch?

@ICHx I use steam-runtime, not steam-native. I guess steam-native may resolve this issue but some games didn't work with it.

I find running steam with STEAM_RUNTIME=0 fixes it on Arch

I'm experiencing the same issue (Fedora 25) but no combination of launching steam with the environmental variables suggested set makes the warnings go away:

STEAM_RUNTIME=0
STEAM_RUNTIME=1
STEAM_RUNTIME_PREFER_HOST_LIBRARIES=0
STEAM_RUNTIME_PREFER_HOST_LIBRARIES=1

Nor does the suggestion I've seen to pin some of the libdbus 32 bit libraries.

ln -s ${HOME}/.local/share/Steam/ubuntu12_32/steam-runtime/i386/lib/i386-linux-gnu/libdbus-1.so.3 ${HOME}/.local/share/Steam/ubuntu12_32/steam-runtime/pinned_libs_32/libdbus-1.so.3

I'm also experiencing crashes in SOMA whenever picking up any object (99% of the time) which disappear when running the non-Steam binary, which may be related.

Computer Information:
    Manufacturer:  Unknown
    Model:  Unknown
    Form Factor: Desktop
    No Touch Input Detected

Processor Information:
    CPU Vendor:  AuthenticAMD
    CPU Brand:  AMD Phenom(tm) II X4 955 Processor
    CPU Family:  0x10
    CPU Model:  0x4
    CPU Stepping:  0x3
    CPU Type:  0x0
    Speed:  3600 Mhz
    4 logical processors
    4 physical processors
    HyperThreading:  Unsupported
    FCMOV:  Supported
    SSE2:  Supported
    SSE3:  Supported
    SSSE3:  Unsupported
    SSE4a:  Supported
    SSE41:  Unsupported
    SSE42:  Unsupported
    AES:  Unsupported
    AVX:  Unsupported
    CMPXCHG16B:  Supported
    LAHF/SAHF:  Supported
    PrefetchW:  Unsupported

Operating System Version:
    Linux (64 bit)
    Kernel Name:  Linux
    Kernel Version:  4.12.9-200.fc25.x86_64
    X Server Vendor:  Fedora Project
    X Server Release:  11903000
    X Window Manager:  GNOME Shell
    Steam Runtime Version:  steam-runtime-beta-release_2017-07-24

Video Card:
    Driver:  NVIDIA Corporation GeForce GT 1030/PCIe/SSE2
    Driver Version:  4.5.0 NVIDIA 384.69
    OpenGL Version: 4.5
    Desktop Color Depth: 24 bits per pixel
    Monitor Refresh Rate: 60 Hz
    VendorID:  0x10de
    DeviceID:  0x1d01
    Revision Not Detected
    Number of Monitors:  1
    Number of Video Cards Not Detected
    Primary Display Resolution:  1920 x 1080
    Desktop Resolution: 1920 x 1080
    Primary Display Size: 20.91" x 11.77" (23.98" diag)
                                            53.1cm x 29.9cm (60.9cm diag)
    Primary Bus: PCI Express 4x
    Primary VRAM: 2048 MB
    Supported MSAA Modes:  2x 4x 8x 16x 

Sound card:
    Audio device: %s1

Memory:
    RAM:  3947 Mb

Miscellaneous:
    UI Language:  English
    LANG:  en_GB.UTF-8
    Total Hard Disk Space Available:  238357 Mb
    Largest Free Hard Disk Block:  33063 Mb
    VR Headset: None detected

Recent Failure Reports:

process 15354: arguments to dbus_connection_unref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2794.
This is normally a bug in some application using the D-Bus library.
Game removed: AppID 282140 "SOMA", ProcID 15515 
No cached sticky mapping in ActivateActionSet.process 15354: arguments to dbus_connection_ref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2656.
This is normally a bug in some application using the D-Bus library.

This is being repeated a good 10+ times a second in my system logs. Any ideas how to stop it?

As for abc-mikey, none of the fixes appear to work for me. With STEAM_RUNTIME_PREFER_HOST_LIBRARIES=1 I do get extra errors:

(steam:857): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

gets logged to the console a couple dozen times before the other errors start (Kubuntu 17.04, AMD A8-7600).

AFAIR this is new in the last week or so, I don't recall updating anything else in that time so I suspect it's from the steam end of things.

I did try soft linking the runtime libdbus-1.so.3 to my systems one but it didn't help.

Under Fedora 25, Steam beta, none of the suggestion help, and STEAM_RUNTIME=0 makes Steam freeze when attempting to auto-login.

My Linux is - 3.16.0-4-amd64 #1 SMP Debian 3.16.43-2+deb8u5 (2017-09-19) x86_64 GNU/Linux
Optimus is enabled and primus-libs packages installed, including i386.

STEAM_RUNTIME=0
STEAM_RUNTIME=1
STEAM_RUNTIME_PREFER_HOST_LIBRARIES=0
STEAM_RUNTIME_PREFER_HOST_LIBRARIES=1

ln -s ${HOME}/.local/share/Steam/ubuntu12_32/steam-runtime/i386/lib/i386-linux-gnu/libdbus-1.so.3 ${HOME}/.local/share/Steam/ubuntu12_32/steam-runtime/pinned_libs_32/libdbus-1.so.3

I tried all of these but no luck. Steam opening but game is not.

** SOLVED ** but I don't get it.

It was working about 2 days ago. Game Launch Setting was setted up to;
optirun %command%
I changed it to:
primusrun %command%

This works for me.
P.S. libriary soft link pinned right now.

ArchLinux: Linux RECOLICPC 4.13.3-1-ARCH #1 SMP PREEMPT Thu Sep 21 20:33:16 CEST 2017 x86_64 GNU/Linux
with core/dbus 1.10.24-1 core/glibc 2.26-4 (base)
Screen freezes while loading CS:GO Map...

Oct 05 23:03:42 RECOLICPC steam.desktop[1307]: process 1568: arguments to dbus_connection_ref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2656.
10月 05 23:03:42 RECOLICPC steam.desktop[1307]: This is normally a bug in some application using the D-Bus library.
10月 05 23:03:42 RECOLICPC steam.desktop[1307]: process 1568: arguments to dbus_connection_unref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2794.
10月 05 23:03:42 RECOLICPC steam.desktop[1307]: This is normally a bug in some application using the D-Bus library.

I installed nvidia driver(extra/nvidia 387.12-1), and made lots of rolling upgrade after last successful launch.

This is not causing me any issues AFAIK however in the process of debugging a gnome error I looked in my journalctl and saw a MASSIVE amount of spam relating to this however it was specifically for starbound. (I launched the starbound.desktop with steam closed)

Oct 10 21:27:40 strangemonkey Starbound.desktop[1527]: process 1687: arguments to dbus_connection_unref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2794.
Oct 10 21:27:40 strangemonkey Starbound.desktop[1527]: This is normally a bug in some application using the D-Bus library.
Oct 10 21:27:40 strangemonkey Starbound.desktop[1527]: process 1687: arguments to dbus_connection_unref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2794.
Oct 10 21:27:40 strangemonkey Starbound.desktop[1527]: This is normally a bug in some application using the D-Bus library.
Oct 10 21:27:40 strangemonkey Starbound.desktop[1527]: process 1687: arguments to dbus_connection_ref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2656.
Oct 10 21:27:40 strangemonkey Starbound.desktop[1527]: This is normally a bug in some application using the D-Bus library.
Oct 10 21:27:40 strangemonkey Starbound.desktop[1527]: process 1687: arguments to dbus_connection_unref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../dbus/dbus-connection.c line 2794.
Oct 10 21:27:40 strangemonkey Starbound.desktop[1527]: This is normally a bug in some application using the D-Bus library.

AMD R9 390x, Arch Linux 4.12.13 let me know if you need any other information.
Like I said, this isn't (at least that I can tell) causing any issues for me other than spamming logs that I'm using to debug a different problem.

To alleviate dbus-related segfaults - (not their root causes), you can:

export DBUS_FATAL_WARNINGS=0

(Note, this does not correct the NULL path issues with dbus, it just stops the segfault, and is another issue entirely: https://github.com/ValveSoftware/steam-for-linux/issues/5201)

Have this:
Oct 26 20:54:39 NEXUS-ONE org.gnome.Shell.desktop[1672]: process 14347: arguments to dbus_connection_ref() were incorrect, assertion "connection->generation == _dbus_current_generation" failed in file ../../../dbus/dbus-connection.c line 2688.
Oct 26 20:54:39 NEXUS-ONE org.gnome.Shell.desktop[1672]: This is normally a bug in some application using the D-Bus library.

As well happen in Ubuntu 17.10 release version with vanilla gnome desktop. but instead clogging the terminal it clogs the syslog for about 62 MB per day writing the same entry about 8-12 times per second to /var/log/syslog. I call this critical because it adds unnecessary write cycles to my SSD.

Only workaround I found so far is starting steam from terminal with the following command (beware you wont see anything output anymore ;) )

steam > /dev/null 2>&1

See https://github.com/systemd/systemd/issues/6432 where the systemd devs need convincing that apps that spam 60mb of useless and annoying data actually exists, to consider adding filtering to journald at collection time.

But I'm sure they'll just say "fix steam" or "fix dbus."
Anyway, at least I plugged the issue reference.

@folknor im sitting here now since release of Ubuntu 17.10 and try to figure out how to stop logging for certain apps at collection time. this would definitively help it to have that.

folknor.. I am on a non systemd 'arch', and I also get this.. it isn't systemd specific, as I don't have any systemd libs whatsoever. Although of course , when a system log is spammed, it can get messy which can be brought up.. I wa smoving stuff of a ntfs drive and had a bunch of issues which spammed my syslog so badly ,)

Depending on how much dbus is annoying you, I have a patch to shut it up for this exact situation..

Patch dbus with this patch and start apps with DBUS_SILENCE_WARNINGS=1 to hide all the dbus spam.

I'm still reproducing this with the current version and it's pretty bad just how frequent the messages are. Just in the last 15 minutes since booting my system there have been 3775 lines in my journal written by Steam regarding this dbus error. I'd really like a fix that isn't just piping all Steam output to /dev/null or custom patching dbus.

https://github.com/ValveSoftware/steam-for-linux/issues/3831

Been an issue since 2015 :/

This issue arises when legacy libraries included in the Steam runtime conflict with newer software installed on the system. The simplest mitigation is to set STEAM_RUNTIME_PREFER_HOST_LIBRARIES=1. This will not impact warnings from libdbusmenu-glib if the system doesn't have the appropriate libdbusmenu packages installed as it will keep using the problematic runtime library with the system's version of dbus. Setting STEAM_RUNTIME=0 also works; however, it requires the libraries present in the runtime to be installed on the system.

It is also possible to remedy the issue without negatively impacting Steam or games that depend on Steam's runtime by deleting the links to the offending libraries from the pinned_libs_* folders Steam creates at ~/.local/share/Steam/ubuntu12_32/steam-runtime. This forces Steam to use the libraries installed on the system without setting flags. As with the previous mitigations the libraries must be installed on the system for Steam to fall back on or one will encounter errors.

pinned_libs_32 contains four links to libraries that must be removed to properly mitigate the issue:
libdbus-1.so.3: Direct cause of the reported issue.
libdbusmenu-glib.so.4: Causes the following warning "LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent."
libdbusmenu-gtk.so.4
libgtk-x11-2.0.so.0: If left after removing libdbus-1.so.3, libdbusmenu-glib.so.4 and libdbusmenu-gtk.so.4 it will prevent Steam's appindicator/status icon from working properly.

pinned_libs_64 contains 2 links which should also be removed:
libdbusmenu-glib.so.4
libdbusmenu-gtk.so.4

This is not a permanent fix as Steam will recreate these links during/after updates (OS/System updates or Steam client updates with the former being the most frequent culprit). Valve needs to remove these from the runtime or adopt more modern versions to permanently fix the issue.

While it is generally not fatal the issue has a noteworthy impact on affected systems. On an Arch Linux test system where the application was installed on February 1, 2018 and allowed to run with the issue unmitigated for about five days it generated hundreds of thousands of lines in the system journal, bloating it to over 1 GiB. Not only does this bury useful information in a sea of frequently repeated output it can result it older logs being purged prematurely once the journal's maximum size is reached. This could easily result in the loss of important log information users may have otherwise wished to preserve and consult when tracking other issues or assessing system health.

Depending on the user's distribution and how they chose to configure logging the effects of this issue could proliferate to the point where it fills up the host filesystem, seriously impairing normal system operation.

On Ubuntu 18.04 I think I have a related crash on steam client startup, exporting STEAM_RUNTIME_PREFER_HOST_LIBRARIES=0 seems to fix it

I think this has been fixed in the May 16th update. I'm not seeing this anymore. And the client no longer crashes if you use your system libdbus-1.so.3 instead of the steam i386 one.

I can confirm that as well, the issue is now gone.

Can also confirm, I no longer get this issue.

Aug 08 2018
Ubuntu 18.04
No message anymore.

It works for me to edit the Run.sh script on:

~./local/share/Steam/steamapps/common/WormsWMD/

export DBUS_FATAL_WARNINGS=0
export MESA_LOADER_DRIVER_OVERRIDE=i965
export STEAM_RUNTIME_PREFER_HOST_LIBRARIES=0
export STEAM_RUNTIME=0

This is the file:

`#!/bin/bash

export LC_ALL=C
export DBUS_FATAL_WARNINGS=0
export MESA_LOADER_DRIVER_OVERRIDE=i965
export STEAM_RUNTIME_PREFER_HOST_LIBRARIES=0
export STEAM_RUNTIME=0
export LD_LIBRARY_PATH="/usr/lib:/usr/local/lib"
chmod a+x ./Worms\ W.M.Dx64
./Worms\ W.M.Dx64`