I can startx as root, but can't as a regular user. I compared logs and there's the difference:root: #> cat Xorg.0.log | egrep '(EE|WW)'[  1507.647] Current Operating System: Linux hostname 3.17.2-1-ARCH #1 SMP PREEMPT Thu Oct 30 20:49:39 CET 2014 x86_64    (WW) warning, (EE) error, (NI) not implemented, (??) unknown.[  1507.658] (WW) Open ACPI failed (/var/run/acpid.socket) (No such file or directory)[  1507.668] (WW) Falling back to old probe method for fglrx[  1507.672] (WW) fglrx: No matching Device section for instance (BusID PCI:0@1:0:1) found[  1507.674] (WW) fglrx(0): board is an unknown third party board, chipset is supported[  1507.864] (WW) fglrx(0): Option VendorName is not used[  1507.864] (WW) fglrx(0): Option ModelName is not used[  1508.002] (EE) AIGLX error: failed to open /usr/X11R6/lib64/modules/dri/fglrx_dri.so, error[/usr/X11R6/lib64/modules/dri/fglrx_dri.so: cannot open shared object file: No such file or directory](and X starts )regular user: $> cat Xorg.0.log | egrep '(EE|WW)'[   533.461] Current Operating System: Linux hostname 3.17.2-1-ARCH #1 SMP PREEMPT Thu Oct 30 20:49:39 CET 2014 x86_64    (WW) warning, (EE) error, (NI) not implemented, (??) unknown.[   533.465] (WW) Open ACPI failed (/var/run/acpid.socket) (No such file or directory)[   533.482] (WW) Falling back to old probe method for fglrx[   533.486] (WW) LoadKernelModule: Setting of real/effective user Id to 0/0 failed[   533.487] ukiDynamicMajor: found major device number 251[   533.488] (WW) fglrx: No matching Device section for instance (BusID PCI:0@1:0:1) found[   533.488] (WW) VGA arbiter: cannot open kernel arbiter, no multi-card support[   533.489] (WW) LoadKernelModule: Setting of real/effective user Id to 0/0 failed[   533.490] ukiDynamicMajor: found major device number 251[   533.490] (EE) fglrx(0): The graphics processor is already set to console mode, set X mode fail. Cannot start X.[   533.490] (EE) fglrx(0): PreInit failed[   533.490] (EE) Screen(s) found, but none have a usable configuration.[   533.490] (EE) [   533.490] (EE) no screens found(EE) [   533.490] (EE) [   533.490] (EE) Please also check the log file at /home/me/.local/share/xorg/Xorg.0.log for additional information.[   533.490] (EE) [   533.492] (EE) Server terminated with error (1). Closing log file.The first difference isLoadKernelModule: Setting of real/effective user Id to 0/0 failedWhat can I do to get it working?Similar question: Why won't my X Server won't start as a regular user?Can't it be the same problem? his x log looks different
Arch: can't get X to work under regular user
arch linux;xorg
You should double check the permissions on /usr/bin/X, it should have SUID/GUID bits set:-rwsr-sr-x 1 root root 10184 Jan  3  2013 /usr/bin/X*change with sudo chmod ug+s /usr/bin/X