soffice startet in bash and closed without visibility or return

I was on the way to start on 29. March 15 at morning my work with LibreOffice on documentation.
I started LibreOffice from the Starter Panel orientated on the left side of the desktop
The mouse cursor changed to the running circle but nothing was visible to me.
More than 10 seconds later I received the ubunut Crash Report alert with the details of Xserver crash.
The System state at this moment was updated and the systemtime was changed succesful to CEST.
I started to Python scripts in two bash shells on last week ran over the weekend.
Both bash shells were closed.
I started a new bash shell and typed "which libreoffice" and started then libreoffice from there.
I started top in this bash shell.
I started a new bash shell and typed "which soffice" and started then soffice from there observing the top output.
I observed in top the process soffce started and seconds later closed without any visibility of soffice on Desktop.

System-Specification:
ubuntu 14.04 TLS
Memory: 15,5 GiB
CPU: Intel® Core™ i7-4770 CPU @ 3.40GHz × 8
Graphics: Intel® Haswell Desktop
Platform: x86_a64 (64 Bit)
Harddisk: 229,3 GB

Xorg.0.log:
X Protocol Version 11, Revision 0
[ 287.401] Build Operating System: Linux 3.2.0-76-generic x86_64 Ubuntu
[ 287.401] Current Operating System: Linux nameofthepc 3.13.0-48-generic #80-Ubuntu SMP Thu Mar 12 11:16:15 UTC 2015 x86_64
[ 287.401] Kernel command line: BOOT_IMAGE=/vmlinuz-3.13.0-48-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=7
[ 287.401] Build Date: 12 February 2015 02:49:29PM
[ 287.401] xorg-server 2:1.15.1-0ubuntu2.7 (For technical support please see http://www.ubuntu.com/support)
[ 287.401] Current version of pixman: 0.30.2
...
[ 287.401] (==) Log file: "/var/log/Xorg.0.log", Time: Mon Mar 30 10:43:47 2015

May it be a stupid question, but when reboot finished initialized by myself Libreoffice was visible.

Kind regards