I installed and reinstalled multiple times the latest version of Opera (44.0.2510.1449) and each time I start it I got the following error :

$ opera
[1]    5247 segmentation fault  opera

When I use ldd on /usr/bin/opera, libffmpeg.so is missing :

$ ldd /usr/bin/opera | grep 'not found'
    libffmpeg.so => not found

But the file is here :

$ ll /usr/lib64/opera/libffmpeg.so
-rw-r--r-- 1 root root 1551320 Apr 24 19:04 /usr/lib64/opera/libffmpeg.so

If I ldd opera binary in /usr/lib64/opera the library is found :

$ ldd opera | grep ffmpeg     
    libffmpeg.so => /usr/lib64/opera/././libffmpeg.so (0x00007f4e68992000)

Starting directly the binary inside that directory produce the same issue. So I backtrace through gdb after the crash :

(gdb) run --single-process
Starting program: /usr/lib64/opera/opera --single-process
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
0x000000000045efbb in ?? ()
(gdb) bt
#0  0x000000000045efbb in  ()
#1  0x000000000503dcd5 in __start_google_malloc ()
#2  0x0000000000456833 in calloc ()
#3  0x00007ffff6b89611 in g_malloc0 () at /usr/lib64/libglib-2.0.so.0
#4  0x00007ffff6e79af7 in  () at /usr/lib64/libgobject-2.0.so.0
#5  0x00007ffff6e7e132 in g_type_register_static () at /usr/lib64/libgobject-2.0.so.0
#6  0x00007ffff6e7e49d in g_type_register_static_simple () at /usr/lib64/libgobject-2.0.so.0
#7  0x00007ffff1ac7cf4 in gdk_display_manager_get_type () at /usr/lib64/libgdk-x11-2.0.so.0
#8  0x00007ffff1ac7d39 in gdk_display_manager_get () at /usr/lib64/libgdk-x11-2.0.so.0
#9  0x00007ffff1e9e3bb in  () at /usr/lib64/libgtk-x11-2.0.so.0
#10 0x00007ffff1e858db in  () at /usr/lib64/libgtk-x11-2.0.so.0
#11 0x00007ffff6b8ff87 in g_option_context_parse () at /usr/lib64/libglib-2.0.so.0
#12 0x00007ffff1e85daa in gtk_parse_args () at /usr/lib64/libgtk-x11-2.0.so.0
#13 0x00007ffff1e85e29 in gtk_init () at /usr/lib64/libgtk-x11-2.0.so.0
#14 0x000000000464f3e6 in  ()
#15 0x000000000464c98f in  ()
#16 0x000000000464f166 in  ()
#17 0x0000000000454f69 in _start ()

I reproduced that step at multiple times and I always end-up with the following last call :

#0  0x000000000045efbb in  ()

So I also tried to use strace, here the last lines :

$ strace opera
open("/usr/share/X11/locale/locale.dir", O_RDONLY) = 7
fstat(7, {st_mode=S_IFREG|0644, st_size=37040, ...}) = 0
read(7, "\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"..., 4096) = 4096
read(7, "CALE\t\t\tes_NI.ISO8859-1\niso8859-1"..., 4096) = 4096
read(7, "E\t\t\tph_PH.ISO8859-1\niso8859-2/XL"..., 4096) = 4096
read(7, "-8\nen_US.UTF-8/XLC_LOCALE\t\t\ten_B"..., 4096) = 4096
read(7, "_PT.UTF-8\nen_US.UTF-8/XLC_LOCALE"..., 4096) = 4096
read(7, "\niso8859-15/XLC_LOCALE:\t\t\tde_CH."..., 4096) = 4096
read(7, "ALE:\t\t\thu_HU.ISO8859-2\narmscii-8"..., 4096) = 4096
read(7, "/XLC_LOCALE:\t\t\tzh_CN.eucCN\nzh_CN"..., 4096) = 4096
close(7)                                = 0
access("/usr/share/X11/locale/en_US.UTF-8/XLC_LOCALE", R_OK) = 0
open("/usr/share/X11/locale/en_US.UTF-8/XLC_LOCALE", O_RDONLY) = 7
fstat(7, {st_mode=S_IFREG|0644, st_size=4251, ...}) = 0
read(7, "\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"..., 4096) = 4096
read(7, "\n \n#\tcs20 class\ncs15\t{\n\tside\t\tGR"..., 4096) = 155
read(7, "", 4096)                       = 0
close(7)                                = 0
rt\_sigaction(SIGPIPE, {SIG_IGN, [PIPE], SA_RESTORER|SA_RESTART, 0x7f98d77da640}, {SIG_IGN, [PIPE],         SA_RESTORER|SA_RESTART, 0x7f98d77da640}, 8) = 0
futex(0x7f98dd4a2468, FUTEX_WAKE_PRIVATE, 2147483647) = 0
--- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0xfffffffffffffdd9} ---
+++ killed by SIGSEGV +++
[1]    5671 segmentation fault  strace opera

Well...here my locale :

$ locale
LANG=en_US.UTF-8
LC_CTYPE=en_US.UTF-8
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE=C
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=

To finish some of my GTK libraries version :

gtk+-1.2.10-x86_64-5                      
gtk+2-2.24.31-x86_64-1                    
gtk+3-3.22.12-x86_64-1                    
gtkmm2-2.24.4-x86_64-1                    
gtkmm3-3.22.0-x86_64-1                    
gtkspell-2.0.16-x86_64-3                  
gtkmm-2.24.2-x86_64-2alien                
webkitgtk3-2.4.11-x86_64-1sl    

Well, let me know if you need further details. But I'm stuck since one week and it really hurt my feelings to use Firefox or Chromium