Hi Andre,
From the wiki page I answered you before, you could get information why you receive this error. Or you can look at the GDB tutorial online to get more info about using it.
So after you run the program in the debug mode, and you get the error, you run the command "backtrace" (or "bt" is the same) to see where this problem originated. For example:
0x000000010409c714 in std::vector<ns3::Ptr<ns3::Application>, std::allocator<ns3::Ptr<ns3::Application> > >::size (this=0x40) at stl_vector.h:400
400 { return size_type(this->_M_impl._M_finish - this->_M_impl._M_start); }
(gdb) bt
#0 0x000000010409c714 in std::vector<ns3::Ptr<ns3::Application>, std::allocator<ns3::Ptr<ns3::Application> > >::size (this=0x40) at stl_vector.h:400
#1 0x0000000103f3dcf1 in ns3::Node::AddApplication (this=0x0, application=@0x7fff5fbfd4a0) at node.cc:144
#2 0x000000010211021b in ns3::OnOffHelper::InstallPriv (this=0x7fff5fbfd758, node=@0x7fff5fbfd520) at on-off-helper.cc:74
#3 0x00000001021106c9 in ns3::OnOffHelper::Install (this=0x7fff5fbfd758, node=@0x7fff5fbfe828) at on-off-helper.cc:48
#4 0x0000000100009db9 in main (argc=2, argv=0x7fff5fbffa20) at andre.cc:197
So if you go to line 197 in your code (at least the copy I made) you will see where it all starts. It's a problem with the install of an application.
You have 5 wifi nodes ( uint32_t nWifi = 5; ) and you install the application on the node 8th ( ApplicationContainer apps = onoff.Install(wifiStaNodes.Get(7)); )
Regards,
K.