As far a 1.3.1 goes, here is the report from tonights 2 identical flights. Happened about the same elapsed time as well. iMac 27 OSX 10.9.2 (Mavericks)   From Apple crash report:   Crashed Thread:  0  Dispatch queue: com.apple.main-thread  Exception Type:  EXC_BAD_ACCESS (SIGSEGV) Exception Codes: EXC_I386_GPFLT   Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0   mac.xpl                           0x00000000830541c1 comp(SilverLining::Renderable*, SilverLining::Renderable*) + 97 1   mac.xpl                           0x0000000083054661 void std::__final_insertion_sort<__gnu_cxx::__normal_iterator<SilverLining::Renderable**, std::vector<SilverLining::Renderable*, SilverLiningAllocator<SilverLining::Renderable*> > >, bool (*)(SilverLining::Renderable*, SilverLining::Renderable*)>(__gnu_cxx::__normal_iterator<SilverLining::Renderable**, std::vector<SilverLining::Renderable*, SilverLiningAllocator<SilverLining::Renderable*> > >, __gnu_cxx::__normal_iterator<SilverLining::Renderable**, std::vector<SilverLining::Renderable*, SilverLiningAllocator<SilverLining::Renderable*> > >, bool (*)(SilverLining::Renderable*, SilverLining::Renderable*)) + 289 2   mac.xpl                           0x0000000083053eb8 SilverLining::Renderer::SortAndDrawBlendedObjects(bool, bool) + 24 3   mac.xpl                           0x000000008300f9f7 SilverLining::Atmosphere::DrawObjects(bool, bool, bool, float, bool) + 3527 4   mac.xpl                           0x000000008300435a drawClouds(int, int, void*) + 411 (abridged)   Like others report, sometimes some flights are OK, then tonight CTD.    I thought it might be the XSB weather push, so I set XP to "0" weather refresh time.  That didn't change anything.   I too absolutely enjoy flying in the SkyMaxx environment, but to not be able to complete flights causes anxiety. "when will this sim crash".   ONLY two bad players are X-Squalkbox and Skymaxx Pro.   FWIW,   Greg