I have a very similar bug with X2Go Client V. 4.0.3.1 (Qt - 4.8.1). x2go-INFO-1> "Starting x2goclient..." x2go-INFO-4> "Translator: :/x2goclient_fr_fr installed." x2go-INFO-5> "Translator: :/qt_fr_FR installed." x2go-INFO-3> "Started x2goclient." [Thread 0xb26ffb40 (LWP 25778) exited] x2go-INFO-8> "Starting connection to server: 192.168.1.11:22" [New Thread 0xb26ffb40 (LWP 28264)] Program received signal SIGSEGV, Segmentation fault. 0xb6ee2814 in QString::operator=(QString const&) () from /usr/lib/i386-linux-gnu/libQtCore.so.4 (gdb) quit Here is the stack with libqt4-dbg, 4:4.8.5 version : (gdb) start Function "main" not defined. Make breakpoint pending on future shared library load? (y or [n]) Starting program: /usr/bin/x2goclient [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1". x2go-INFO-1> "Starting x2goclient..." x2go-INFO-4> "Translator: :/x2goclient_fr_fr installed." x2go-INFO-5> "Translator: :/qt_fr_FR installed." x2go-INFO-3> "Started x2goclient." x2go-INFO-8> "Starting connection to server: 192.168.1.11:22" [New Thread 0xb2e62b40 (LWP 31128)] Program received signal SIGSEGV, Segmentation fault. QString::operator= (this=0xbffff024, other=...) at tools/qstring.cpp:1410 1410 tools/qstring.cpp: Aucun fichier ou dossier de ce type. (gdb) bt #0 QString::operator= (this=0xbffff024, other=...) at tools/qstring.cpp:1410 #1 0x080a7cdc in ?? () #2 0x080a89b6 in ?? () #3 0x0814420e in ?? () #4 0xb6fc80f7 in QMetaObject::activate (sender=0x8537c08, m=0x8155698, local_signal_index=0, argv=0xbffff4d0) at kernel/qobject.cpp:3539 #5 0x08145a1f in ?? () #6 0x08105b81 in ?? () #7 0x08145c68 in ?? () #8 0xb6fc48aa in QMetaCallEvent::placeMetaCall (this=0xb3311408, object=0x8537c08) at kernel/qobject.cpp:524 #9 0xb6fcc6fb in QObject::event (this=0x8537c08, e=0xb3311408) at kernel/qobject.cpp:1194 #10 0xb73a37f4 in QApplicationPrivate::notify_helper (this=0x8288f38, receiver=0x8537c08, e=0xb3311408) at kernel/qapplication.cpp:4567 #11 0xb73aa2d3 in QApplication::notify (this=0xbffffb58, receiver=0x8537c08, e=0xb3311408) at kernel/qapplication.cpp:4353 #12 0xb6fb2e4a in QCoreApplication::notifyInternal (this=0xbffffb58, receiver=receiver@entry=0x8537c08, event=event@entry=0xb3311408) at kernel/qcoreapplication.cpp:953 #13 0xb6fb670d in sendEvent (event=0xb3311408, receiver=0x8537c08) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231 #14 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x8289048) at kernel/qcoreapplication.cpp:1577 #15 0xb6fb6c1c in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1470 #16 0xb6fe323e in sendPostedEvents () at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:236 #17 postEventSourceDispatch (s=0x8289da0) at kernel/qeventdispatcher_glib.cpp:287 #18 0xb65df1e3 in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0 #19 0xb65df468 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0 #20 0xb65df528 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0 #21 0xb6fe293b in QEventDispatcherGlib::processEvents (this=this@entry=0x8289b68, flags=...) at kernel/qeventdispatcher_glib.cpp:434 #22 0xb74585de in QGuiEventDispatcherGlib::processEvents (this=0x8289b68, flags=...) at kernel/qguieventdispatcher_glib.cpp:204 #23 0xb6fb1823 in QEventLoop::processEvents (this=this@entry=0xbffffad8, flags=...) at kernel/qeventloop.cpp:149 #24 0xb6fb1b49 in QEventLoop::exec (this=this@entry=0xbffffad8, flags=...) at kernel/qeventloop.cpp:204 ---Type to continue, or q to quit--- #25 0xb6fb78fe in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225 #26 0xb73a1a24 in QApplication::exec () at kernel/qapplication.cpp:3828 #27 0x0812a533 in ?? () #28 0x0805bd3b in ?? () #29 0xb6b81a83 in __libc_start_main (main=0x805bd20, argc=1, argv=0xbffffc94, init=0x8148de0, fini=0x8148e50, rtld_fini=0xb7fed180 <_dl_fini>, stack_end=0xbffffc8c) at libc-start.c:287 #30 0x0805bdc1 in ?? () I'm not a C/C++ developer so this is difficult to me to investigate that. -- Marc