Hi Dear All I use vGate72.vdi, Ubuntu 64-bit in Oracle VirtualBox.5.1.8_2. I know what is the problem but I don't know how to solve it. The problem is in attaching system. Every system has a defined shape and layers according to Gate Users’ Guide V.7.2. page 137. The system which I want to simulate has 16 trapezoid detectors which are 14*14 arrays (with dimensions of 6.95*6.95 mm2 at the face and 6.95*12.05 mm2 at the end) of trapezoid crystals with dimension of 0.45*0.45 mm2 and 0.45*0.814 mm2 at the front and back respectively. I used PETscanner with a single trapezoid crystal and there was no problem when I attach it to system. Since 14 trapezoid crystals have different orientation and length from center to the edge I have to define them separately in box module then I can repeat that module on the other direction. So I will have 14 sublayers. I can decrease it to 7 sublayers by repeating the submodule that they are embedded in, right below the original one inversely. But in PETscanner we can attach just 5 levels and there are no sublevels. I can’t define crystals in different levels in PETscanner because they are for the same depth. I checked it for 2 crystals and when I attached the system and ran it there was an error “COMMAND NOT FOUND </gate/systems/PETscanner/level5/attach crystal2”. Then, I tried a trick. I used OPET instead, which have 5 depths and 8 layers in the last depth. I defined the rsector, module and the crystal as a box and defined the layers as trapezoid crystals. But in OPET the last level should be wedge. So when I run the simulation I encounter that crash that I send you before. As you see in following. I want to know if there is any solution in which I can define a system with trapezoid crystals and at least 7 layer in the same depth. Please help me. There was a crash. > > This is the entire stack trace of all threads: > > =========================================================== > > . > > . > > . > > #29 0x00007f9e7429b975 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #30 0x00007f9e7397e87a in QMetaObject::activate(QObject*, QMetaObject > const*, int, void**) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 > > #31 0x00007f9e742a2a6c in QLineControl::processKeyEvent(QKeyEvent*) () > from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #32 0x00007f9e7429808a in QLineEdit::keyPressEvent(QKeyEvent*) () from > /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #33 0x00007f9e73eeb3e4 in QWidget::event(QEvent*) () from > /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #34 0x00007f9e7429d3c1 in QLineEdit::event(QEvent*) () from > /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #35 0x00007f9e73e9be2c in QApplicationPrivate::notify_helper(QObject*, > QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #36 0x00007f9e73ea36f1 in QApplication::notify(QObject*, QEvent*) () > from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #37 0x00007f9e7396a4dd in QCoreApplication::notifyInternal(QObject*, > QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 > > #38 0x00007f9e73f3b027 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #39 0x00007f9e73f3b3c9 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #40 0x00007f9e73f15417 in QApplication::x11ProcessEvent(_XEvent*) () > from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #41 0x00007f9e73f3db32 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #42 0x00007f9e6f382e04 in g_main_context_dispatch () from > /lib/x86_64-linux-gnu/libglib-2.0.so.0 > > #43 0x00007f9e6f383048 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 > > #44 0x00007f9e6f3830ec in g_main_context_iteration () from > /lib/x86_64-linux-gnu/libglib-2.0.so.0 > > #45 0x00007f9e739977a1 in > QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) > () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4 > > #46 0x00007f9e73f3dbe6 in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 > > #47 0x00007f9e739690af in > QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from > /usr/lib/x86_64-linux-gnu/libQtCore.so.4 > > #48 0x00007f9e739693a5 in > QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from > /usr/lib/x86_64-linux-gnu/libQtCore.so.4 > > #49 0x00007f9e7396eb79 in QCoreApplication::exec() () from > /usr/lib/x86_64-linux-gnu/libQtCore.so.4 > > #50 0x00007f9e7d7ce16d in G4UIQt::SessionStart (this=0x2922b60) at > /home/gate/Progs/Geant4/geant4.10.02/source/interfaces/basic/src/G4UIQt.cc:811 > > #51 0x0000000000612075 in main ()