After solving the problem of the maps on my MAC, I'm playing normally even in larger maps.
However, on base attack missions, the game crashes with a segmentation fault after some turns while aliens are moving.
The error reported by the system, after the crash on a base attack is:
Process: ufo [651]
Path: /Users/USER/*/ufo
Identifier: ufo
Version: 0
Code Type: X86-64 (Native)
Parent Process: bash [509]
Responsible: Terminal [500]
User ID: 502
Date/Time: 2015-11-01 22:26:30.001 +0000
OS Version: Mac OS X 10.10.5 (14F1021)
Report Version: 11
Anonymous UUID: A253C178-20B4-3E38-68EE-8C0917EB932F
Time Awake Since Boot: 4800 seconds
Crashed Thread: 4 GameThread
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000
VM Regions Near 0:
-->
__TEXT 000000010f8ef000-000000010fc2e000 [ 3324K] r-x/rwx SM=COW /Users/USER/*
Thread 0:: Dispatch queue: com.apple.main-thread
0 libsystem_kernel.dylib 0x00007fff8c3de3fa __select + 10
1 ufo 0x000000010fa57711 Qcommon_Frame() + 1041 (common.cpp:1527)
2 ufo 0x000000010fb3e60d main + 93 (osx_main.cpp:70)
3 libdyld.dylib 0x00007fff915445c9 start + 1
Thread 1:: Dispatch queue: com.apple.libdispatch-manager
0 libsystem_kernel.dylib 0x00007fff8c3df232 kevent64 + 10
1 libdispatch.dylib 0x00007fff8bd8426e _dispatch_mgr_thread + 52
Thread 2:: com.apple.audio.IOThread.client
0 libsystem_kernel.dylib 0x00007fff8c3d94de mach_msg_trap + 10
1 libsystem_kernel.dylib 0x00007fff8c3d864f mach_msg + 55
2 com.apple.audio.CoreAudio 0x00007fff8d0c8544 HALB_MachPort::SendMessageWithReply(unsigned int, unsigned int, unsigned int, unsigned int, mach_msg_header_t*, bool, unsigned int) + 98
3 com.apple.audio.CoreAudio 0x00007fff8d0c84d2 HALB_MachPort::SendSimpleMessageWithSimpleReply(unsigned int, unsigned int, int, int&, bool, unsigned int) + 42
4 com.apple.audio.CoreAudio 0x00007fff8d0c6a05 HALC_ProxyIOContext::IOWorkLoop() + 1089
5 com.apple.audio.CoreAudio 0x00007fff8d0c64f2 HALC_ProxyIOContext::IOThreadEntry(void*) + 88
6 com.apple.audio.CoreAudio 0x00007fff8d0c63c3 HALB_IOThread::Entry(void*) + 157
7 libsystem_pthread.dylib 0x00007fff8f4fc05a _pthread_body + 131
8 libsystem_pthread.dylib 0x00007fff8f4fbfd7 _pthread_start + 176
9 libsystem_pthread.dylib 0x00007fff8f4f93ed thread_start + 13
Thread 3:
0 libsystem_kernel.dylib 0x00007fff8c3d94de mach_msg_trap + 10
1 libsystem_kernel.dylib 0x00007fff8c3d864f mach_msg + 55
2 com.apple.CoreFoundation 0x00007fff8c777eb4 __CFRunLoopServiceMachPort + 212
3 com.apple.CoreFoundation 0x00007fff8c77737b __CFRunLoopRun + 1371
4 com.apple.CoreFoundation 0x00007fff8c776bd8 CFRunLoopRunSpecific + 296
5 com.apple.AppKit 0x00007fff917e256b _NSEventThread + 137
6 libsystem_pthread.dylib 0x00007fff8f4fc05a _pthread_body + 131
7 libsystem_pthread.dylib 0x00007fff8f4fbfd7 _pthread_start + 176
8 libsystem_pthread.dylib 0x00007fff8f4f93ed thread_start + 13
Thread 4 Crashed:: GameThread
0 game.dylib 0x0000000134e06640 G_MissionThink(Edict*) + 1248
1 game.dylib 0x0000000134dfd453 G_EdictsThink() + 195
2 game.dylib 0x0000000134e0441b G_RunFrame() + 379
3 ufo 0x000000010fa96265 SV_RunGameFrame() + 21 (sv_game.cpp:761)
4 ufo 0x000000010fa96202 SV_RunGameFrameThread(void*) + 66 (sv_game.cpp:747)
5 libSDL2-2.0.0.dylib 0x00000001110b880a SDL_RunThread + 60
6 libSDL2-2.0.0.dylib 0x00000001110f1233 RunThread + 9
7 libsystem_pthread.dylib 0x00007fff8f4fc05a _pthread_body + 131
8 libsystem_pthread.dylib 0x00007fff8f4fbfd7 _pthread_start + 176
9 libsystem_pthread.dylib 0x00007fff8f4f93ed thread_start + 13
Thread 4 crashed with X86 Thread State (64-bit):
rax: 0x0000000000000000 rbx: 0x00007f8e40f02320 rcx: 0x000000012939d050 rdx: 0x000000012939d438
rdi: 0x000000012939d050 rsi: 0x0000000000000000 rbp: 0x0000000134ff7e10 rsp: 0x0000000134ff7d90
r8: 0x0000000000000000 r9: 0x0000000000000003 r10: 0x00007f8e45e00000 r11: 0x0000000000008889
r12: 0x000000010fa961c0 r13: 0x00000000000008ff r14: 0x00007f8e45fd5260 r15: 0x0000000000000000
rip: 0x0000000134e06640 rfl: 0x0000000000010202 cr2: 0x0000000000000000
Logical CPU: 4
Error Code: 0x00000004
Trap Number: 14
