Hi Vincent, this appears to be another recent regression, this time from r35832 on Monday.
Keycodes: \Av\Ae\AhY\A% To reproduce: 1) Press Alt-V, E to split the Screen 2) Press Alt-H, Y to Open Help->LyX Functions 3) Press X I then get the Assert: /usr/include/c++/4.4/debug/vector:272:error: attempt to subscript container with out-of-bounds index 0, but container only holds 0 elements. Objects involved in the operation: sequence "this" @ 0x0x1c29648 { type = NSt7__debug6vectorIN3lyx7TocItemESaIS2_EEE; [New Thread 0x7fffe7739710 (LWP 15633)] Program received signal SIGABRT, Aborted. 0x00007ffff51dea75 in *__GI_raise (sig=<value optimised out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64 64 ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory. in ../nptl/sysdeps/unix/sysv/linux/raise.c (gdb) #0 0x00007ffff51dea75 in *__GI_raise (sig=<value optimised out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64 cpp abort.c #1 0x00007ffff51e25c0 in *__GI_abort () at abort.c:92 #2 0x00007ffff5c4a63d in __gnu_debug::_Error_formatter::_M_error() const () from /usr/lib/libstdc++.so.6 #3 0x0000000000cf9fb3 in std::__debug::vector<lyx::TocItem, std::allocator<lyx::TocItem> >::operator[](unsigned long) const () #4 0x0000000000d0587c in lyx::frontend::TocModel::tocItem (this=0x1c1bbc0, cpp TocModel.cpp index=<value optimised out>) at TocModel.cpp:120 #5 0x0000000000d07711 in lyx::frontend::TocModel::updateItem (this=0x1c1bbc0, cpp TocModel.cpp dit=<value optimised out>) at TocModel.cpp:149 #6 0x0000000000d078f7 in lyx::frontend::TocModels::updateItem ( cpp TocModel.cpp this=0x1971788, type=..., dit=...) at TocModel.cpp:342 #7 0x0000000000c98d67 in lyx::frontend::GuiView::updateTocItem ( cpp GuiView.cpp this=0x1970d20, type=<value optimised out>, dit=...) at GuiView.cpp:1390 #8 0x000000000094e4c2 in lyx::TocBackend::updateItem ( this=<value optimised out>, dit=<value optimised out>) cpp TocBackend.cpp at TocBackend.cpp:164 #9 0x00000000009b7720 in lyx::Cursor::checkBufferStructure (this=0x1fafe18) cpp Cursor.cpp at Cursor.cpp:2377 #10 0x00000000009090ab in lyx::Text::insertChar (this=0x1d44130, cur=..., cpp Text.cpp ... For more information see: http://gmatht.homelinux.net/xp/keytest/html_out/out/t10/html/1288188721.html -- John C. McCabe-Dansted