I found later on the day after (after restarting) the game then worked.
After the beta update it was forever loading but later on it somehow worked
On 2 Feb 2015 02:29, "Mikhail" [email protected] wrote:

Game update: AppID 20920 "The Witcher 2: Assassins of Kings Enhanced
Edition", ProcID 10574, IP 0.0.0.0:0
ERROR: ld.so: object
'/home/mikhail/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from
LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object
'/home/mikhail/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from
LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object
'/home/mikhail/.local/share/Steam/ubuntu12_64/gameoverlayrenderer.so' from
LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS64): ignored.

(desktop-launcher:10576): Gtk-WARNING **: Unable to locate theme engine in
module_path: "adwaita",

(desktop-launcher:10576): Gtk-WARNING *

: Unable to locate theme engine in module_path: "adwaita",
/usr/share/themes/Adwaita/gtk-2.0/gtkrc:1163: error: unexpected identifier
direction', expected character}' Gtk-Message: Failed to load module
"pk-gtk-module" * Message: window size should be 487x713
ERROR: ld.so: object
'/home/mikhail/.local/share/Steam/ubuntu12_64/gameoverlayrenderer.so' from
LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS64): ignored.
ERROR - eON failed to initialise!
Game removed: AppID 20920 "The Witcher 2: Assassins of Kings Enhanced
Edition", ProcID 10574

Processor Information:
Vendor: GenuineIntel
CPU Family: 0x6
CPU Model: 0x3c
CPU Stepping: 0x3
CPU Type: 0x0
Speed: 3900 Mhz
8 logical processors
4 physical processors
HyperThreading: Supported
FCMOV: Supported
SSE2: Supported
SSE3: Supported
SSSE3: Supported
SSE4a: Unsupported
SSE41: Supported
SSE42: Supported

Network Information:
Network Speed:

Operating System Version:
"Fedora release 21 (Twenty One)" (64 bit)
Kernel Name: Linux
Kernel Version: 3.18.5-200.fc21.x86_64+debug
X Server Vendor: Fedora Project
X Server Release: 11602901
X Window Manager: GNOME Shell
Steam Runtime Version: steam-runtime-release_2015-01-06

Video Card:
Driver: Intel Open Source Technology Center Mesa DRI Intel(R) Haswell
Desktop

Driver Version: 3.0 Mesa 10.4.3
OpenGL Version: 3.0
Desktop Color Depth: 24 bits per pixel
Monitor Refresh Rate: 60 Hz
VendorID: 0x8086
DeviceID: 0x412
Number of Monitors: 1
Number of Logical Video Cards: 1
Primary Display Resolution: 1920 x 1080
Desktop Resolution: 1920 x 1080
Primary Display Size: 20,04" x 11,26" (22,95" diag)
50,9cm x 28,6cm (58,3cm diag)
Primary VRAM Not Detected

Sound card:
Audio device: Intel Haswell HDMI

Memory:
RAM: 31079 Mb

Miscellaneous:
UI Language: English
LANG: en_US.utf8
Microphone: Not set
Total Hard Disk Space Available: 3815446 Mb
Largest Free Hard Disk Block: 468062 Mb

Installed software:

Recent Failure Reports:

—
Reply to this email directly or view it on GitHub
https://github.com/ValveSoftware/steam-for-linux/issues/3698.

Very old my report looks like affected by Kernel problem.
Details here: https://news.softpedia.com/news/Linus-Torvalds-to-Patch-the-Kernel-for-a-Witcher-2-Problem-471046.shtml

In nowadays prevents to run this game only the problem with the EULA confirmation: https://github.com/ValveSoftware/steam-for-linux/issues/5489