Created attachment 831254 [details]
Xorg log with version 2.21.15-5

Created attachment 831255 [details]
dmesg with version 2.21.15-5

Created attachment 831256 [details]
Xorg log with version 2.21.15-4

Created attachment 831257 [details]
dmesg with version 2.21.15-4

Seem to be having the same problem. Get a black screen after upgrading Fedora 20 x64 on a ThinkPad W500. Managed to repoduce the problem after reinstalling the system. Updated on both 28 and 29 December.

Fix: Change graphics card from automatic selection of discrete/integrated to forced integrated in BIOS.

I have hit the same issue.

extracted from my journalctl-logs:
Jan 04 15:41:28 localhost gnome-session[1092]: Entering running state
Jan 04 15:41:32 localhost gnome-session[1092]: Window manager warning: Log level 6: The program 'gnome-shell' received an X Window System error.
Jan 04 15:41:32 localhost gnome-session[1092]: This probably reflects a bug in the program.
Jan 04 15:41:32 localhost gnome-session[1092]: The error was 'BadMatch (invalid parameter attributes)'.
Jan 04 15:41:32 localhost gnome-session[1092]: (Details: serial 348 error_code 8 request_code 139 minor_code 30)
Jan 04 15:41:32 localhost gnome-session[1092]: (Note to programmers: normally, X errors are reported asynchronously;
Jan 04 15:41:32 localhost gnome-session[1092]: that is, you will receive the error a while after causing it.
Jan 04 15:41:32 localhost gnome-session[1092]: To debug your program, run it with the GDK_SYNCHRONIZE environment
Jan 04 15:41:32 localhost gnome-session[1092]: variable to change this behavior. You can then get a meaningful
Jan 04 15:41:32 localhost gnome-session[1092]: backtrace from your debugger if you break on the gdk_x_error() function.)
Jan 04 15:41:32 localhost kernel: traps: gnome-shell[1247] trap int3 ip:7f2aea9ad4e9 sp:7fffb0785e60 error:0
Jan 04 15:41:33 localhost gnome-session[1092]: (gnome-settings-daemon:1212): media-keys-plugin-WARNING **: 2: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name :1.7 was not provided by any .service files

The fix(es) mentioned above also works for me

The same bug on Acer Aspire Timeline X 4820 T. Can post additional information if required.

Got this bug on a Thinkpad W400 as well as a W500. I'd say its quite serious as it renders a new install useless for a non-expert user (user ends up with a blank screen upon first login after install/first package update).

This happened to me as well, however downgrading to xorg-x11-drv-intel-2.21.15-4.fc20.x86_64 does not fix it for me. My only option was to uninstall the package. I can login now but I am stuck with vesa I guess. Any help would be appreciated, thanks.

This has also happens to me on HP Pavilion dv6 Notebook PC with
    Intel(R) Graphics Media Accelerator HD
    ATI Mobility Radeon HD 5470
when using the Intel graphics with driver
    xorg-x11-drv-intel-2.21.15-5.fc20.x86_64

This does, however, work with the LightDM and the Cinnamon or Xfce desktop.

Downgrading to the driver
    xorg-x11-drv-intel-2.21.15-4.fc20.x86_64
fixes the problem with the Gnome desktop manager and shell, viz.
    gdm.x86_64                1:3.10.0.1-1.fc20
    gnome-shell.x86_64        3.10.3-4.fc20 


Messages are

gnome-session[1156]: Window manager warning: Log level 6: The program 'gnome-shell' received an X Window System erro
gnome-session[1156]: This probably reflects a bug in the program.
gnome-session[1156]: The error was 'BadMatch (invalid parameter attributes)'.
gnome-session[1156]: (Details: serial 353 error_code 8 request_code 139 minor_code 30)
gnome-session[1156]: (Note to programmers: normally, X errors are reported asynchronously;
gnome-session[1156]: that is, you will receive the error a while after causing it.
gnome-session[1156]: To debug your program, run it with the GDK_SYNCHRONIZE environment
gnome-session[1156]: variable to change this behavior. You can then get a meaningful
gnome-session[1156]: backtrace from your debugger if you break on the gdk_x_error() function.)
kernel: traps: gnome-shell[1329] trap int3 ip:7f55c68b44e9 sp:7fff23ce9710 error:0
.
.
.
gnome-session[1156]: gnome-session[1156]: WARNING: Application 'gnome-shell.desktop' killed by signal 5
gnome-session[1156]: (gnome-settings-daemon:1224): media-keys-plugin-WARNING **: 2: GDBus.Error:org.freedesktop.DBus
gnome-session[1156]: WARNING: Application 'gnome-shell.desktop' killed by signal 5
gnome-session[1156]: ** (gnome-shell:1379): WARNING **: Couldn't register with accessibility bus: Did not receive a 
gnome-session[1156]: Window manager warning: Log level 6: The program 'gnome-shell' received an X Window System erro
gnome-session[1156]: This probably reflects a bug in the program.
gnome-session[1156]: The error was 'BadMatch (invalid parameter attributes)'.
gnome-session[1156]: (Details: serial 354 error_code 8 request_code 139 minor_code 30)
gnome-session[1156]: (Note to programmers: normally, X errors are reported asynchronously;
gnome-session[1156]: that is, you will receive the error a while after causing it.
gnome-session[1156]: To debug your program, run it with the GDK_SYNCHRONIZE environment
gnome-session[1156]: variable to change this behavior. You can then get a meaningful
gnome-session[1156]: backtrace from your debugger if you break on the gdk_x_error() function.)
kernel: traps: gnome-shell[1379] trap int3 ip:7f701482c4e9 sp:7fffba232d20 error:0
gnome-session[1156]: gnome-session[1156]: WARNING: Application 'gnome-shell.desktop' killed by signal 5
gnome-session[1156]: gnome-session[1156]: WARNING: App 'gnome-shell.desktop' respawning too quickly
gnome-session[1156]: WARNING: Application 'gnome-shell.desktop' killed by signal 5
gnome-session[1156]: WARNING: App 'gnome-shell.desktop' respawning too quickly
gnome-session[1156]: Unrecoverable failure in required component gnome-shell.desktop
...

Actually, I determined a workaround for my problem, it may not be related to this bug report.

I have an i5-4670K with Intel HD Graphics 4600 and am using 3 monitors via VGA, DVI, and HDMI. If I unplug the HDMI monitor I am able to login. Once the KDE session is running, I can plug the HDMI monitor back in and everything works. But if I log out or reboot I have to unplug it again.

Further to my comment (#10),

Downgrading to the driver
    xorg-x11-drv-intel-2.21.15-4.fc20.x86_64
fixes the problem with the Gnome desktop manager and shell, viz.
    gdm.x86_64                1:3.10.0.1-1.fc20
    gnome-shell.x86_64        3.10.3-4.fc20 

HOWEVER, with this older driver, I cannot use the discrete ATI
graohics card because of the known bug with xorg-x11-drv-intel-2.21.15.4
 xrandr --setprovideroffloadsink fails 
in
    xorg-x11-drv-intel-2.21
which also occurs on my machine (HP Pavilion dv6 Notebook).

(See the now, I believe, closed
    Red Hat Bugzilla – Bug 1033903
    xrandr --setprovideroffloadsink fails on Lenovo Y470p)

So, for me, a fix for the no graphical login problem with
xorg-x11-drv-intel-2.21.15-5.fc20.x86_64 would be most welcome.

Cheers.

This bug affects me too in a newly installed F20 with Gnome-shell
lspci output for VGA:
00:02.0 VGA compatible controller [0300]: Intel Corporation Core Processor Integrated Graphics Controller [8086:0046] (rev 02)
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Park [Mobility Radeon HD 5430/5450/5470] [1002:68e0] (rev ff)

I had to downgrade to xorg-x11-drv-intel-2.21.15-4.fc20.x86_64

cheers

Further to my comments (#10 & #12), a further minor comment

When using the Intel graphics with driver
    xorg-x11-drv-intel-2.21.15-5.fc20.x86_64

everything also works with the kdm + kde, and the kdm + cinnamon.

To summarise ...

It appears there are only problems with  the gdm (gdm-1:3.10.0.1-1.fc20.x86_64)
and the gnome-shell (gnome-shell-3.10.2.1-2.fc20.x86_64), viz.
(1) There is no user chooser - login screen - when using the gdm,
(2) If the gnome shell is selected from another DM, it crashes, so no desktop.

I'm currently using the LightDM + Cinnamon, so that I can use the discrete
graphics card (via DRI_PRIME=1).

Cheers.

Still happening with xorg-x11-drv-intel-2.21.15-7.fc20.x86_64.

Sorry for the slow response, but likewise for me, gdm-1:3.10.0.1-1.fc20.x86_64
does not work for me either with the newer
  xorg-x11-drv-intel-2,21,15-7.fc20.x86_64
It starts the gnome shell: command is "gnome-shell --mode=gdm startup-id=..."
which still subsequently crashes (as per the listing above), and is, presumably,
the reason why I get no user chooser/login screen.
I haven't registered this as a gnome-shell bug, but I guess I should.

The good news for me at that I am now able to use the Gnome shell as my Display
Manager - this became functional at some time on or after xorg-x11-drv-intel
was updated -I attempted to use it about two weeks ago, and found it worked!

So, for me, item 2 in (my) comment 14 is now fixed, and  I am now using the
LightDM + Gnome shell.

Cheers.

I had forgotten about this bug until I got an update for xorg-x11-drv-intel today.  Whether due to this update or to some other in kernel, gdm or gnome-shell, there's no bug for me now with an up to date system.

xorg-x11-drv-intel-2.21.15-9.fc20.x86_64
gnome-shell-3.10.4-9.fc20.x86_64
gdm-3.10.0.1-1.fc20.x86_64
kernel-3.17.3-200.fc20.x86_64

Desktop appeared with two screens, with the mouse going into the void over the border, despite only having one, but that's a different issue, easy to solve from the screen settings.

So, I don't know about the other people affected, but for me, this is solved.

I got the update to xorg-x11-drv-intel yesterday (Nov 22nd) to
    xorg-x11-drv-intel-2.21.15-9.fc20.x86_64
and this seems to have fixed the problem (no graphical login screen) for me also.

The problem was, summarising from previously.

gnome-session[1156]: Window manager warning: Log level 6: The program 'gnome-shell' received an X Window System error
gnome-session[1156]: This probably reflects a bug in the program.

and subsequently

kernel: traps: gnome-shell[1329] trap int3 ip:7f55c68b44e9 sp:7fff23ce9710 error:0

and ultimately no graphcal login (user chooser) screen.

I do now get the graphical login screen.

The versions giving problems were
    xorg-x11-drv-intel-2.21.15-5.fc20.x86_64
    xorg-x11-drv-intel-2.21.15-7.fc20.x86_64

So, I am very pleased to be able to use the gdm again :-).

There's no place like Gnome.

Sadly xorg-x11-drv-intel-2.21.15-9.fc20.x86_64 does not fixes the problem for me. I had to downgrade to xorg-x11-drv-intel-2.21.15-4.fc20.x86_64

Fedora 20 x86_64 fully updated with gdm + gnome shell 

# cat /proc/cpuinfo
....
model name	: Intel(R) Core(TM) i3-3225 CPU @ 3.30GHz
...
Using integrated grahic card, with DVI and analog outputs in mirror mode

# lspci
...
00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor Graphics Controller (rev 09)
...

*** Bug 1128572 has been marked as a duplicate of this bug. ***

This message is a reminder that Fedora 20 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 20. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
this bug will be closed as EOL if it remains open with a Fedora  'version'
of '20'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version.

Thank you for reporting this issue and we are sorry that we were not 
able to fix it before Fedora 20 is end of life. If you would still like 
to see this bug fixed and are able to reproduce it against a later version 
of Fedora, you are encouraged  change the 'version' to a later Fedora 
version prior this bug is closed as described in the policy above.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events. Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

Fedora 20 changed to end-of-life (EOL) status on 2015-06-23. Fedora 20 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of
Fedora please feel free to reopen this bug against that version. If you
are unable to reopen this bug, please file a new report against the
current release. If you experience problems, please add a comment to this
bug.

Thank you for reporting this bug and we are sorry it could not be fixed.