When starting 'wireshark' I get error:

$ wireshark
Fontconfig warning: "/etc/fonts/conf.d/53-monospace-lcd-filter.conf", line 10: Having multiple values in <test> isn't supported and may not work as expected
(wireshark:30329): GLib-GObject-WARNING **: The property GtkSettings:gtk-menu-images is deprecated and shouldn't be used anymore. It will be removed in a future version.
(wireshark:30329): GLib-GObject-WARNING **: The property GtkToolButton:stock-id is deprecated and shouldn't be used anymore. It will be removed in a future version.
Segmentation fault

I have Jessie amd64 and am updated.
What is the problem ?

A segfault happens when a program is doing something with memory it shouldn't be. Writing outside of the bounds of an array, that sort of thing.

It points to a problem with the wireshark source, not your system. Search wireshark's bug tracker (or your distro's bug tracker for 'wireshark'), see if it is a known issue. Perhaps file a bug.

---------- Post added Oct 4th, 2014 at 08:45 AM ----------

Oh, and if you have any experience with C and/or debugging, running the program through 'strace' or with gdb might give you a better idea where the problem is.

I have filed a bug report.