then the game crashed, the log is in the spoiler below.
I was building a big concrete platform with a blueprint and the personal roboport.
I was walking on it and the bots built it without problems and then at some time the game crashed.
Log
0.001 2015-07-17 18:38:50; Factorio 0.12.0 (Build 103, win64)
0.001 Operating system: Windows 8
0.001 Read data path: C:/Program Files/Factorio/data
0.001 Write data path: C:/Program Files/Factorio
0.001 Binaries path: C:/Program Files/Factorio/bin
0.510 Initialised Direct3D: NVIDIA GeForce GTX 660 Ti; driver: nvd3dumx.dll 9.18.13.5306
0.540 Graphics options: [FullScreen: true] [VSync: true] [UIScale: 100%] [MultiSampling: X 8] [Graphics quality: normal] [Video memory usage: all]
0.623 Loading mod core 0.0.0 (data.lua)
0.625 Loading mod base 0.12.0 (data.lua)
1.110 Initial atlas bitmap size is 16384
1.113 Created atlas bitmap 16384x7658
7.889 Info Updater.cpp:720: Downloading https://www.factorio.com/updater/get-av ... iVersion=2
8.583 0 packages available to download (experimental updates enabled).
8.623 Factorio initialised
54.231 Loading map C:/Program Files\Factorio\saves\nur_so.zip
54.310 Info Scenario.cpp:160: Map version 0.11.21-1
54.313 Info PrototypeMigrationList.cpp:94: Activating migration base/2015-06-01_Factorio_0.12.0.json
54.643 Applying migration: Base Mod: 2015-07-02_Factorio_0.12.0.lua
Factorio crashed. Generating symbolized stacktrace, please wait ...
c:\temp\factorio-5829127a\libraries\stackwalker\stackwalker.cpp (923): StackWalker::ShowCallstack
c:\temp\factorio-5829127a\src\util\logger.cpp (283): Logger::writeStacktrace
c:\temp\factorio-5829127a\src\util\logger.cpp (337): Logger::logStacktrace
c:\temp\factorio-5829127a\src\util\crashhandler.cpp (79): CrashHandler::writeStackTrace
c:\temp\factorio-5829127a\src\util\crashhandler.cpp (88): CrashHandler::SehHandler
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD12F1C72)
00007FFDD12F1C72 (KERNELBASE): (filename not available): UnhandledExceptionFilter
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD407FB33)
00007FFDD407FB33 (ntdll): (filename not available): memset
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD4062896)
00007FFDD4062896 (ntdll): (filename not available): _C_specific_handler
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD4073F0D)
00007FFDD4073F0D (ntdll): (filename not available): _chkstk
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD4034887)
00007FFDD4034887 (ntdll): (filename not available): RtlRaiseException
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD407309A)
00007FFDD407309A (ntdll): (filename not available): KiUserExceptionDispatcher
c:\temp\factorio-5829127a\src\item\itemstack.cpp (111): ItemStack::operator--
c:\temp\factorio-5829127a\src\entity\constructionrobot.cpp (437): ConstructionRobot::update
c:\temp\factorio-5829127a\src\surface\chunk.cpp (438): Chunk::update
c:\temp\factorio-5829127a\src\surface\surface.cpp (733): Surface::update
c:\temp\factorio-5829127a\src\map\map.cpp (897): Map::update
c:\temp\factorio-5829127a\src\game.cpp (135): Game::update
c:\temp\factorio-5829127a\src\scenario\scenario.cpp (736): Scenario::update
c:\temp\factorio-5829127a\src\mainloop.cpp (250): MainLoop::gameUpdateStep
c:\temp\factorio-5829127a\src\mainloop.cpp (351): MainLoop::updateLoop
c:\boost_1_58_0\boost\function\function_template.hpp (160): boost::detail::function::void_function_obj_invoker0<boost::_bi::bind_t<void,void (__cdecl*)(ThreadBarrier * __ptr64,boost::chrono::time_point<boost::chrono::steady_clock,boost::chrono::duration<__int64,boost::ratio<1,1000000000> > > * __ptr64,boost::chrono::time_point<boost::chrono::steady_clock,boost::chrono::duration<__int64,boost::ratio<1,1000000000> > > * __ptr64,bool * __ptr64,bool),boost::_bi::list5<boost::_bi::value<ThreadBarrier * __ptr64>,boost::_bi::value<boost::chrono::time_point<boost::chrono::steady_clock,boost::chrono::duration<__int64,boost::ratio<1,1000000000> > > * __ptr64>,boost::_bi::value<boost::chrono::time_point<boost::chrono::steady_clock,boost::chrono::duration<__int64,boost::ratio<1,1000000000> > > * __ptr64>,boost::_bi::value<bool * __ptr64>,boost::_bi::value<bool> > >,void>::invoke
c:\temp\factorio-5829127a\src\util\thread.cpp (34): Thread::loop
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FF6F8ECB163)
00007FF6F8ECB163 (Factorio): (filename not available): boost::`anonymous namespace'::thread_start_function
f:\dd\vctools\crt\crtw32\startup\threadex.c (376): _callthreadstartex
f:\dd\vctools\crt\crtw32\startup\threadex.c (354): _threadstartex
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD2FA13D2)
00007FFDD2FA13D2 (KERNEL32): (filename not available): BaseThreadInitThunk
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD3FF5444)
00007FFDD3FF5444 (ntdll): (filename not available): RtlUserThreadStart
3390.922 Error Util.cpp:45: Unexpected error occurred. You can help us to solve the problem by posting the contents of the log file on the Factorio forums.
0.001 Operating system: Windows 8
0.001 Read data path: C:/Program Files/Factorio/data
0.001 Write data path: C:/Program Files/Factorio
0.001 Binaries path: C:/Program Files/Factorio/bin
0.510 Initialised Direct3D: NVIDIA GeForce GTX 660 Ti; driver: nvd3dumx.dll 9.18.13.5306
0.540 Graphics options: [FullScreen: true] [VSync: true] [UIScale: 100%] [MultiSampling: X 8] [Graphics quality: normal] [Video memory usage: all]
0.623 Loading mod core 0.0.0 (data.lua)
0.625 Loading mod base 0.12.0 (data.lua)
1.110 Initial atlas bitmap size is 16384
1.113 Created atlas bitmap 16384x7658
7.889 Info Updater.cpp:720: Downloading https://www.factorio.com/updater/get-av ... iVersion=2
8.583 0 packages available to download (experimental updates enabled).
8.623 Factorio initialised
54.231 Loading map C:/Program Files\Factorio\saves\nur_so.zip
54.310 Info Scenario.cpp:160: Map version 0.11.21-1
54.313 Info PrototypeMigrationList.cpp:94: Activating migration base/2015-06-01_Factorio_0.12.0.json
54.643 Applying migration: Base Mod: 2015-07-02_Factorio_0.12.0.lua
Factorio crashed. Generating symbolized stacktrace, please wait ...
c:\temp\factorio-5829127a\libraries\stackwalker\stackwalker.cpp (923): StackWalker::ShowCallstack
c:\temp\factorio-5829127a\src\util\logger.cpp (283): Logger::writeStacktrace
c:\temp\factorio-5829127a\src\util\logger.cpp (337): Logger::logStacktrace
c:\temp\factorio-5829127a\src\util\crashhandler.cpp (79): CrashHandler::writeStackTrace
c:\temp\factorio-5829127a\src\util\crashhandler.cpp (88): CrashHandler::SehHandler
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD12F1C72)
00007FFDD12F1C72 (KERNELBASE): (filename not available): UnhandledExceptionFilter
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD407FB33)
00007FFDD407FB33 (ntdll): (filename not available): memset
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD4062896)
00007FFDD4062896 (ntdll): (filename not available): _C_specific_handler
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD4073F0D)
00007FFDD4073F0D (ntdll): (filename not available): _chkstk
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD4034887)
00007FFDD4034887 (ntdll): (filename not available): RtlRaiseException
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD407309A)
00007FFDD407309A (ntdll): (filename not available): KiUserExceptionDispatcher
c:\temp\factorio-5829127a\src\item\itemstack.cpp (111): ItemStack::operator--
c:\temp\factorio-5829127a\src\entity\constructionrobot.cpp (437): ConstructionRobot::update
c:\temp\factorio-5829127a\src\surface\chunk.cpp (438): Chunk::update
c:\temp\factorio-5829127a\src\surface\surface.cpp (733): Surface::update
c:\temp\factorio-5829127a\src\map\map.cpp (897): Map::update
c:\temp\factorio-5829127a\src\game.cpp (135): Game::update
c:\temp\factorio-5829127a\src\scenario\scenario.cpp (736): Scenario::update
c:\temp\factorio-5829127a\src\mainloop.cpp (250): MainLoop::gameUpdateStep
c:\temp\factorio-5829127a\src\mainloop.cpp (351): MainLoop::updateLoop
c:\boost_1_58_0\boost\function\function_template.hpp (160): boost::detail::function::void_function_obj_invoker0<boost::_bi::bind_t<void,void (__cdecl*)(ThreadBarrier * __ptr64,boost::chrono::time_point<boost::chrono::steady_clock,boost::chrono::duration<__int64,boost::ratio<1,1000000000> > > * __ptr64,boost::chrono::time_point<boost::chrono::steady_clock,boost::chrono::duration<__int64,boost::ratio<1,1000000000> > > * __ptr64,bool * __ptr64,bool),boost::_bi::list5<boost::_bi::value<ThreadBarrier * __ptr64>,boost::_bi::value<boost::chrono::time_point<boost::chrono::steady_clock,boost::chrono::duration<__int64,boost::ratio<1,1000000000> > > * __ptr64>,boost::_bi::value<boost::chrono::time_point<boost::chrono::steady_clock,boost::chrono::duration<__int64,boost::ratio<1,1000000000> > > * __ptr64>,boost::_bi::value<bool * __ptr64>,boost::_bi::value<bool> > >,void>::invoke
c:\temp\factorio-5829127a\src\util\thread.cpp (34): Thread::loop
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FF6F8ECB163)
00007FF6F8ECB163 (Factorio): (filename not available): boost::`anonymous namespace'::thread_start_function
f:\dd\vctools\crt\crtw32\startup\threadex.c (376): _callthreadstartex
f:\dd\vctools\crt\crtw32\startup\threadex.c (354): _threadstartex
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD2FA13D2)
00007FFDD2FA13D2 (KERNEL32): (filename not available): BaseThreadInitThunk
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FFDD3FF5444)
00007FFDD3FF5444 (ntdll): (filename not available): RtlUserThreadStart
3390.922 Error Util.cpp:45: Unexpected error occurred. You can help us to solve the problem by posting the contents of the log file on the Factorio forums.