I'm trying to import a C# project (closed source) into Umbrello using the "import project" option, but I can't because it crashes during the import process.

Reproducible: Always

Steps to Reproduce:
1. Open the "Code" menu, then the "Active language" submenu and click C#.
2. Open the "Code" menu, then click the "Import project..." command, select the directory containing the C# project and click the "OK" button.

Actual Results:  
I can see some classes from the project are imported looking at the Command history panel, then Umbrello crashes.

Expected Results:  
Do not crash and import the project.

Application: umbrello (2.13.3)
KDE Platform Version: 4.13.3
Qt Version: 4.8.6
Operating System: Linux 3.13.0-43-generic x86_64
Distribution: Ubuntu 14.04.1 LTS

-- Backtrace:
Application: Umbrello UML Modeller (umbrello), signal: Aborted
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7ffaf4e927c0 (LWP 6218))]

Thread 9 (Thread 0x7ffae2d41700 (LWP 6219)):
#0  0x00007ffaf15aabad in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007ffaee0defe4 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ffaee0df0ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffae2d541ad in ?? () from /usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so
#4  0x00007ffaee103f05 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007ffaee5ab182 in start_thread (arg=0x7ffae2d41700) at pthread_create.c:312
#6  0x00007ffaf15b7efd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 8 (Thread 0x7ffae2277700 (LWP 6220)):
#0  0x00007ffaf15aabad in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007ffaee0defe4 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ffaee0df30a in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffae77cd336 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4  0x00007ffaee103f05 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007ffaee5ab182 in start_thread (arg=0x7ffae2277700) at pthread_create.c:312
#6  0x00007ffaf15b7efd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 7 (Thread 0x7ffada0c2700 (LWP 6221)):
#0  0x00007ffaf15c5b04 in pthread_mutex_unlock (mutex=0x24db3a0) at forward.c:194
#1  0x00007ffaee1209b1 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ffaee0df0f6 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffaee0df129 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007ffaee103f05 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007ffaee5ab182 in start_thread (arg=0x7ffada0c2700) at pthread_create.c:312
#6  0x00007ffaf15b7efd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 6 (Thread 0x7ffad98c1700 (LWP 6225)):
#0  __pthread_mutex_unlock_usercnt (decr=1, mutex=0x7ffac8003e30) at pthread_mutex_unlock.c:69
#1  __GI___pthread_mutex_unlock (mutex=0x7ffac8003e30) at pthread_mutex_unlock.c:310
#2  0x00007ffaee1209b1 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffaee0dea59 in g_main_context_check () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007ffaee0def7b in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007ffaee0df0ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#6  0x00007ffaf2cea7be in QEventDispatcherGlib::processEvents (this=0x7ffac8001320, flags=...) at kernel/qeventdispatcher_glib.cpp:436
#7  0x00007ffaf2cbc0af in QEventLoop::processEvents (this=this@entry=0x7ffad98c0de0, flags=...) at kernel/qeventloop.cpp:149
#8  0x00007ffaf2cbc3a5 in QEventLoop::exec (this=this@entry=0x7ffad98c0de0, flags=...) at kernel/qeventloop.cpp:204
#9  0x00007ffaf2bb8c5f in QThread::exec (this=this@entry=0x2678f90) at thread/qthread.cpp:537
#10 0x00007ffaf2c9d823 in QInotifyFileSystemWatcherEngine::run (this=0x2678f90) at io/qfilesystemwatcher_inotify.cpp:265
#11 0x00007ffaf2bbb32f in QThreadPrivate::start (arg=0x2678f90) at thread/qthread_unix.cpp:349
#12 0x00007ffaee5ab182 in start_thread (arg=0x7ffad98c1700) at pthread_create.c:312
#13 0x00007ffaf15b7efd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 5 (Thread 0x7ffaad0f7700 (LWP 6227)):
#0  0x00007ffaf15aabad in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007ffaee0defe4 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ffaee0df0ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffaf2cea7be in QEventDispatcherGlib::processEvents (this=0x7ffaa80008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:436
#4  0x00007ffaf2cbc0af in QEventLoop::processEvents (this=this@entry=0x7ffaad0f6de0, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007ffaf2cbc3a5 in QEventLoop::exec (this=this@entry=0x7ffaad0f6de0, flags=...) at kernel/qeventloop.cpp:204
#6  0x00007ffaf2bb8c5f in QThread::exec (this=this@entry=0x2dafd10) at thread/qthread.cpp:537
#7  0x00007ffaf2c9d823 in QInotifyFileSystemWatcherEngine::run (this=0x2dafd10) at io/qfilesystemwatcher_inotify.cpp:265
#8  0x00007ffaf2bbb32f in QThreadPrivate::start (arg=0x2dafd10) at thread/qthread_unix.cpp:349
#9  0x00007ffaee5ab182 in start_thread (arg=0x7ffaad0f7700) at pthread_create.c:312
#10 0x00007ffaf15b7efd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 4 (Thread 0x7ffaac846700 (LWP 6230)):
#0  0x00007ffaf15af823 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007ffaf2c9a171 in QProcessManager::run (this=0x7ffaf3024540 <processManager()::processManager>) at io/qprocess_unix.cpp:270
#2  0x00007ffaf2bbb32f in QThreadPrivate::start (arg=0x7ffaf3024540 <processManager()::processManager>) at thread/qthread_unix.cpp:349
#3  0x00007ffaee5ab182 in start_thread (arg=0x7ffaac846700) at pthread_create.c:312
#4  0x00007ffaf15b7efd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 3 (Thread 0x7ffad90c0700 (LWP 6234)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007ffaf2bbb816 in wait (time=18446744073709551615, this=0x3235520) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=this@entry=0x2f5fd68, mutex=mutex@entry=0x2f5fd60, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:158
#3  0x00007ffaf2533d96 in QFileInfoGatherer::run (this=0x2f5fd50) at dialogs/qfileinfogatherer.cpp:214
#4  0x00007ffaf2bbb32f in QThreadPrivate::start (arg=0x2f5fd50) at thread/qthread_unix.cpp:349
#5  0x00007ffaee5ab182 in start_thread (arg=0x7ffad90c0700) at pthread_create.c:312
#6  0x00007ffaf15b7efd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 2 (Thread 0x7ffaa7c41700 (LWP 6235)):
#0  0x00007ffaf15aabad in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007ffaee0defe4 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ffaee0df0ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffaf2cea7be in QEventDispatcherGlib::processEvents (this=0x7ffa9c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:436
#4  0x00007ffaf2cbc0af in QEventLoop::processEvents (this=this@entry=0x7ffaa7c40de0, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007ffaf2cbc3a5 in QEventLoop::exec (this=this@entry=0x7ffaa7c40de0, flags=...) at kernel/qeventloop.cpp:204
#6  0x00007ffaf2bb8c5f in QThread::exec (this=this@entry=0x2f61360) at thread/qthread.cpp:537
#7  0x00007ffaf2c9d823 in QInotifyFileSystemWatcherEngine::run (this=0x2f61360) at io/qfilesystemwatcher_inotify.cpp:265
#8  0x00007ffaf2bbb32f in QThreadPrivate::start (arg=0x2f61360) at thread/qthread_unix.cpp:349
#9  0x00007ffaee5ab182 in start_thread (arg=0x7ffaa7c41700) at pthread_create.c:312
#10 0x00007ffaf15b7efd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 1 (Thread 0x7ffaf4e927c0 (LWP 6218)):
[KCrash Handler]
#6  0x00007ffaf14f3bb9 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#7  0x00007ffaf14f6fc8 in __GI_abort () at abort.c:89
#8  0x00007ffaf1530e14 in __libc_message (do_abort=do_abort@entry=1, fmt=fmt@entry=0x7ffaf163f5a8 "*** Error in `%s': %s: 0x%s ***\n") at ../sysdeps/posix/libc_fatal.c:175
#9  0x00007ffaf153d0ee in malloc_printerr (ptr=<optimized out>, str=0x7ffaf163f748 "free(): invalid next size (fast)", action=1) at malloc.c:4996
#10 _int_free (av=<optimized out>, p=<optimized out>, have_lock=0) at malloc.c:3840
#11 0x0000000000501767 in NativeImportBase::~NativeImportBase (this=0x31d6390, __in_chrg=<optimized out>) at ../../umbrello/codeimport/nativeimportbase.cpp:49
#12 0x000000000050a2a9 in CSharpImport::~CSharpImport (this=0x31d6390, __in_chrg=<optimized out>) at ../../umbrello/codeimport/csharp/csharpimport.cpp:51
#13 0x000000000068c8f5 in UMLApp::importFiles (this=this@entry=0x25d1040, fileList=fileList@entry=0x7fffdebf2440) at ../../umbrello/uml.cpp:2570
#14 0x000000000068d0f5 in importFiles (fileList=0x7fffdebf2440, this=0x25d1040) at ../../umbrello/uml.cpp:2561
#15 UMLApp::slotImportProject (this=0x25d1040) at ../../umbrello/uml.cpp:2621
#16 0x00007ffaf2cd187a in QMetaObject::activate (sender=sender@entry=0x264c1d0, m=m@entry=0x7ffaf2b00de0 <QAction::staticMetaObject>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x7fffdebf25a0) at kernel/qobject.cpp:3539
#17 0x00007ffaf2050a62 in QAction::triggered (this=this@entry=0x264c1d0, _t1=false) at .moc/release-shared/moc_qaction.cpp:276
#18 0x00007ffaf2052433 in QAction::activate (this=this@entry=0x264c1d0, event=event@entry=QAction::Trigger) at kernel/qaction.cpp:1257
#19 0x00007ffaf2480489 in QMenuPrivate::activateCausedStack (this=this@entry=0x29266d0, causedStack=..., action=action@entry=0x264c1d0, action_e=action_e@entry=QAction::Trigger, self=self@entry=true) at widgets/qmenu.cpp:1038
#20 0x00007ffaf24849b9 in QMenuPrivate::activateAction (this=0x29266d0, action=0x264c1d0, action_e=action_e@entry=QAction::Trigger, self=self@entry=true) at widgets/qmenu.cpp:1130
#21 0x00007ffaf2488385 in QMenu::mouseReleaseEvent (this=this@entry=0x2925690, e=e@entry=0x7fffdebf2cd0) at widgets/qmenu.cpp:2372
#22 0x00007ffaf3a15665 in KMenu::mouseReleaseEvent (this=0x2925690, e=0x7fffdebf2cd0) at ../../kdeui/widgets/kmenu.cpp:464
#23 0x00007ffaf20a650a in QWidget::event (this=this@entry=0x2925690, event=event@entry=0x7fffdebf2cd0) at kernel/qwidget.cpp:8376
#24 0x00007ffaf24887bb in QMenu::event (this=0x2925690, e=0x7fffdebf2cd0) at widgets/qmenu.cpp:2481
#25 0x00007ffaf2056e2c in QApplicationPrivate::notify_helper (this=this@entry=0x2352110, receiver=receiver@entry=0x2925690, e=e@entry=0x7fffdebf2cd0) at kernel/qapplication.cpp:4567
#26 0x00007ffaf205d5dd in QApplication::notify (this=this@entry=0x7fffdebf34f0, receiver=receiver@entry=0x2925690, e=e@entry=0x7fffdebf2cd0) at kernel/qapplication.cpp:4110
#27 0x00007ffaf395ed1a in KApplication::notify (this=0x7fffdebf34f0, receiver=0x2925690, event=0x7fffdebf2cd0) at ../../kdeui/kernel/kapplication.cpp:311
#28 0x00007ffaf2cbd4dd in QCoreApplication::notifyInternal (this=0x7fffdebf34f0, receiver=receiver@entry=0x2925690, event=event@entry=0x7fffdebf2cd0) at kernel/qcoreapplication.cpp:953
#29 0x00007ffaf205cd93 in sendEvent (event=<optimized out>, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#30 QApplicationPrivate::sendMouseEvent (receiver=receiver@entry=0x2925690, event=event@entry=0x7fffdebf2cd0, alienWidget=alienWidget@entry=0x0, nativeWidget=nativeWidget@entry=0x2925690, buttonDown=buttonDown@entry=0x7ffaf2b3c318 <qt_button_down>, lastMouseReceiver=..., spontaneous=spontaneous@entry=true) at kernel/qapplication.cpp:3178
#31 0x00007ffaf20d1cfc in QETWidget::translateMouseEvent (this=this@entry=0x2925690, event=event@entry=0x7fffdebf3020) at kernel/qapplication_x11.cpp:4568
#32 0x00007ffaf20d1269 in QApplication::x11ProcessEvent (this=0x7fffdebf34f0, event=event@entry=0x7fffdebf3020) at kernel/qapplication_x11.cpp:3627
#33 0x00007ffaf20f8b02 in x11EventSourceDispatch (s=0x23496e0, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#34 0x00007ffaee0dee04 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#35 0x00007ffaee0df048 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#36 0x00007ffaee0df0ec in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#37 0x00007ffaf2cea7a1 in QEventDispatcherGlib::processEvents (this=0x231c8d0, flags=...) at kernel/qeventdispatcher_glib.cpp:434
#38 0x00007ffaf20f8bb6 in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#39 0x00007ffaf2cbc0af in QEventLoop::processEvents (this=this@entry=0x7fffdebf33f0, flags=...) at kernel/qeventloop.cpp:149
#40 0x00007ffaf2cbc3a5 in QEventLoop::exec (this=this@entry=0x7fffdebf33f0, flags=...) at kernel/qeventloop.cpp:204
#41 0x00007ffaf2cc1b79 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#42 0x00007ffaf205537c in QApplication::exec () at kernel/qapplication.cpp:3828
#43 0x0000000000438839 in main (argc=<optimized out>, argv=<optimized out>) at ../../umbrello/main.cpp:123