Can you please open a terminal window, and type steam, then copy / paste the complete output here?

Thanks.

No reply, closing this bug. a3lm4t, if you can reproduce this with the latest release, please re-open.

Sorry to comment on this old issue, but I think I have a similar issue. Steam crashed as soon as I clicked "login to existing account".

Here is the complete console output:

Running Steam on linuxmint 17 64-bit
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/version(1409240101_client)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steamwebhelper)/version(20140828032355)
Installing breakpad exception handler for appid(steamwebhelper)/version(1409196235)
[0918/234020:ERROR:nss_util.cc(1018)] Failed to load NSS libraries.
Installing breakpad exception handler for appid(steamwebhelper)/version(20140828032355)
Installing breakpad exception handler for appid(steamwebhelper)/version(1409196235)
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 78: saw unknown, expected number
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
Installing breakpad exception handler for appid(steam)/version(1409240101)
[0918/234020:ERROR:renderer_main.cc(227)] Running without renderer sandbox
[0918/234020:ERROR:renderer_main.cc(227)] Running without renderer sandbox
Generating new string page texture 12: 48x256, total string texture memory is 49.15 KB
Generating new string page texture 13: 256x256, total string texture memory is 311.30 KB
Generating new string page texture 14: 128x256, total string texture memory is 442.37 KB
Generating new string page texture 15: 384x256, total string texture memory is 835.58 KB
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 78: saw unknown, expected number
Steam: An X Error occurred
X Error of failed request:  BadValue (integer parameter out of range for operation)
Major opcode of failed request:  18 (X_ChangeProperty)
Value in failed request:  0xffffffff
Serial number of failed request:  789
xerror_handler: X failed, continuing
Uploading dump (out-of-process) [proxy '']
/tmp/dumps/assert_20140918234020_1.dmp
/home/energy/.steam/steam.sh: line 730: 16875 Segmentation fault      $STEAM_DEBUGGER "$STEAMROOT/$STEAMEXEPATH" "$@"
Requested Force create but SharedObjectMutex already created
Forced create but already created for SharedObjectEvent
Forced create but already created for SharedObjectEvent
Finished uploading minidump (out-of-process): success = yes
response: CrashID=bp-67ca805f-21be-4616-b8ae-205b32140918

Should I open a new issue or just wait for you to reopen the issue?

@Energy0124 opening a new issue report would be the better option.

@Tele42 Ok. Thank you for your advise. I will open a new issue a bit later.