Can anybody tell me whats wrong with my 12.04/lightdm/XDMCP setup? i activated X11 remote via tcp and XDMCP on lightdm and restarted lightdm: [SeatDefaults] user-session=ubuntu greeter-session=unity-greeter xserver-allow-tcp=true [XDMCPServer] enabled=true whenever i try to login to the remove lightdm via Xephyr Xephyr -query <remote ip> :10 i get the following trace: SELinux: Disabled on system, not enabling in X server [dix] Could not init font path element /usr/share/fonts/X11/cyrillic, removing from list! Ignoring device from udev. Ignoring device from udev. Ignoring device from udev. Ignoring device from udev. Ignoring device from udev. Ignoring device from udev. *** glibc detected *** Xephyr: free(): corrupted unsorted chunks: 0x08659088 *** ======= Backtrace: ========= /lib/i686/cmov/libc.so.6(+0x6af71)[0xb72b6f71] /lib/i686/cmov/libc.so.6(+0x6c7c8)[0xb72b87c8] /lib/i686/cmov/libc.so.6(cfree+0x6d)[0xb72bb8ad] Xephyr(Xfree+0x21)[0x81ddcd1] Xephyr(SrvXkbResizeKeyType+0x59e)[0x81ca01e] Xephyr[0x81ab8eb] Xephyr[0x81ac8c2] Xephyr[0x8088807] Xephyr[0x807c16a] /lib/i686/cmov/libc.so.6(__libc_start_main+0xe6)[0xb7262ca6] Xephyr[0x8061081] ======= Memory map: ======== 08048000-08204000 r-xp 00000000 fd:00 1148994 /usr/bin/Xephyr 08204000-08210000 rw-p 001bc000 fd:00 1148994 /usr/bin/Xephyr 08210000-08239000 rw-p 00000000 00:00 0 08496000-087ac000 rw-p 00000000 00:00 0 [heap] b5600000-b5621000 rw-p 00000000 00:00 0 b5621000-b5700000 ---p 00000000 00:00 0 b5762000-b588f000 rw-p 00000000 00:00 0 b588f000-b58b3000 r-xp 00000000 fd:00 50040 /usr/lib/libexpat.so.1.5.2 b58b3000-b58b5000 rw-p 00024000 fd:00 50040 /usr/lib/libexpat.so.1.5.2 b58d0000-b5ae4000 r-xp 00000000 fd:00 1212530 /usr/lib/dri/swrast_dri.so b5ae4000-b5ae9000 rw-p 00214000 fd:00 1212530 /usr/lib/dri/swrast_dri.so b5ae9000-b5af8000 rw-p 00000000 00:00 0 b5af8000-b5c24000 rw-s 00000000 00:04 1420132375 /SYSV00000000 (deleted) b5c24000-b5c28000 r-xp 00000000 fd:00 770089 /usr/lib/libXfixes.so.3.1.0 b5c28000-b5c29000 rw-p 00003000 fd:00 770089 /usr/lib/libXfixes.so.3.1.0 b5c29000-b5c31000 r-xp 00000000 fd:00 772923 /usr/lib/libXrender.so.1.3.0 b5c31000-b5c32000 rw-p 00007000 fd:00 772923 /usr/lib/libXrender.so.1.3.0 b5c32000-b5c3a000 r-xp 00000000 fd:00 49913 /usr/lib/libXcursor.so.1.0.2 b5c3a000-b5c3b000 rw-p 00007000 fd:00 49913 /usr/lib/libXcursor.so.1.0.2 b5c3b000-b5c58000 r-xp 00000000 09:02 466930 /lib/libgcc_s.so.1 b5c58000-b5c59000 rw-p 0001c000 09:02 466930 /lib/libgcc_s.so.1 b5c59000-b5c5b000 rw-p 00000000 00:00 0 b5c5b000-b7121000 r-xp 00000000 fd:00 49164 /usr/lib/libnvidia-glcore.so.256.53 b7121000-b7178000 rwxp 014c6000 fd:00 49164 /usr/lib/libnvidia-glcore.so.256.53 b7178000-b7188000 rwxp 00000000 00:00 0 b7188000-b7189000 r-xp 00000000 fd:00 49193 /usr/lib/tls/libnvidia-tls.so.256.53 b7189000-b718a000 rw-p 00000000 fd:00 49193 /usr/lib/tls/libnvidia-tls.so.256.53 b718a000-b718b000 rw-p 00000000 00:00 0 b718b000-b7190000 r-xp 00000000 fd:00 50172 /usr/lib/libfontenc.so.1.0.0 b7190000-b7191000 rw-p 00005000 fd:00 50172 /usr/lib/libfontenc.so.1.0.0 b7191000-b71a1000 r-xp 00000000 09:02 466849 /lib/libbz2.so.1.0.4 b71a1000-b71a2000 rw-p 00010000 09:02 466849 /lib/libbz2.so.1.0.4 b71a2000-b71b5000 r-xp 00000000 fd:00 52002 /usr/lib/libz.so.1.2.3.4 b71b5000-b71b6000 rw-p 00013000 fd:00 52002 /usr/lib/libz.so.1.2.3.4 b71b6000-b722a000 r-xp 00000000 fd:00 51162 /usr/lib/libfreetype.so.6.6.0 b722a000-b722e000 rw-p 00073000 fd:00 51162 /usr/lib/libfreetype.so.6.6.0 b722e000-b7246000 r-xp 00000000 fd:00 49652 /usr/lib/libxcb.so.1.1.0 b7246000-b7247000 rw-p 00017000 fd:00 49652 /usr/lib/libxcb.so.1.1.0 b7247000-b7248000 rw-p 00000000 00:00 0 b7248000-b724b000 r-xp 00000000 fd:00 54148 /usr/lib/libgpg-error.so.0.4.0 b724b000-b724c000 rw-p 00002000 fd:00 54148 /usr/lib/libgpg-error.so.0.4.0 b724c000-b738c000 r-xp 00000000 09:02 467095 /lib/i686/cmov/libc-2.11.3.so