Give your crash log maybe ?
0 libsystem_kernel.dylib 0x963ac69e __pthread_kill + 10
1 libsystem_pthread.dylib 0x9b3c9fd5 pthread_kill + 101
2 libsystem_c.dylib 0x91a87efe abort + 156
3 libmonosgen-2.0.1.dylib 0x0015c50f mono_handle_native_sigsegv + 687
4 libmonosgen-2.0.1.dylib 0x001b4f5d sigabrt_signal_handler + 109
5 libsystem_platform.dylib 0x9bdde03b _sigtramp + 43
6 ??? 0xffffffff 0 + 4294967295
7 libmonosgen-2.0.1.dylib 0x001b4ef0 sigusr1_signal_handler + 272
8 libsystem_c.dylib 0x91a87efe abort + 156
9 libmonosgen-2.0.1.dylib 0x0031255c monoeg_g_logv + 188
10 libmonosgen-2.0.1.dylib 0x0031258b monoeg_assertion_message + 43
11 libmonosgen-2.0.1.dylib 0x001c098f mono_class_create_from_typedef + 303
12 libmonosgen-2.0.1.dylib 0x001c1551 mono_class_get_full + 177
13 libmonosgen-2.0.1.dylib 0x001c07ec mono_class_from_name + 1180
14 libmonosgen-2.0.1.dylib 0x001bffca mono_class_from_typeref + 330
15 libmonosgen-2.0.1.dylib 0x001c163a mono_class_get_full + 410
16 libmonosgen-2.0.1.dylib 0x001c16b0 mono_class_get + 32
17 libmonosgen-2.0.1.dylib 0x00221543 mono_metadata_parse_type_internal + 723
18 libmonosgen-2.0.1.dylib 0x0022254d mono_metadata_parse_mh_full + 1021
19 libmonosgen-2.0.1.dylib 0x001f4ede mono_method_get_header + 638
20 libmonosgen-2.0.1.dylib 0x000dab9e mono_method_to_ir + 702
21 libmonosgen-2.0.1.dylib 0x000bc111 mini_method_compile + 5969
22 libmonosgen-2.0.1.dylib 0x000bdceb mono_jit_compile_method_with_opt + 1755
23 libmonosgen-2.0.1.dylib 0x000be9a5 mono_jit_runtime_invoke + 437
24 libmonosgen-2.0.1.dylib 0x0027d9ee mono_runtime_invoke + 126
25 libmonosgen-2.0.1.dylib 0x002848b4 mono_runtime_invoke_array + 1332
26 libmonosgen-2.0.1.dylib 0x001eb3a6 ves_icall_InternalInvoke + 1286
27 ??? 0x00662c00 0 + 6695936
28 ??? 0x00662b30 0 + 6695728
29 ??? 0x00661db0 0 + 6692272
30 ??? 0x00661c0c 0 + 6691852
31 ??? 0x74d8da18 0 + 1960368664
32 ??? 0x74d79b88 0 + 1960287112
33 ??? 0x74d79194 0 + 1960284564
34 ??? 0x00654c9d 0 + 6638749
35 libmonosgen-2.0.1.dylib 0x000beb2c mono_jit_runtime_invoke + 828
36 libmonosgen-2.0.1.dylib 0x0027d9ee mono_runtime_invoke + 126
37 libmonosgen-2.0.1.dylib 0x0027db5c mono_runtime_delegate_invoke + 140
38 libmonosgen-2.0.1.dylib 0x0025526d async_invoke_thread + 2141
39 libmonosgen-2.0.1.dylib 0x0024ef75 start_wrapper + 549
40 libmonosgen-2.0.1.dylib 0x0030db3d inner_start_thread + 253
41 libsystem_pthread.dylib 0x9b3c7ecf _pthread_body + 138
42 libsystem_pthread.dylib 0x9b3c7e45 _pthread_start + 162
43 libsystem_pthread.dylib 0x9b3c5f0e thread_start + 34