Hi guys,
we are dealing with strange crashes using JSON deserialization. We are using this plugin https://www.assetstore.unity3d.com/en/#!/content/11347. Game is crashing when deserializing JSON data. Device is using iOS 7 and Unity was 5.2.3. It looks like, that this type of crash is not 100 %, and I think it depends on iOS version. We have crashes of this type with previous version of unity 5.2.21f, but they occured much less often 
Here is generated c++ method, where crash occurs (line 37):
// System.Boolean System.Collections.Generic.Dictionary`2<System.Object,System.Object>::TryGetValue(TKey,TValue&)
extern TypeInfo* ArgumentNullException_t1_1500_il2cpp_TypeInfo_var;
extern TypeInfo* Object_t_il2cpp_TypeInfo_var;
extern Il2CppCodeGenString* _stringLiteral793;
extern "C" bool Dictionary_2_TryGetValue_m1_15085_gshared (Dictionary_2_t1_1952 * __this, Object_t * ___key, Object_t ** ___value, const MethodInfo* method)
{
static bool s_Il2CppMethodIntialized;
if (!s_Il2CppMethodIntialized)
{
ArgumentNullException_t1_1500_il2cpp_TypeInfo_var = il2cpp_codegen_type_info_from_index(3);
Object_t_il2cpp_TypeInfo_var = il2cpp_codegen_type_info_from_index(0);
_stringLiteral793 = il2cpp_codegen_string_literal_from_index(793);
s_Il2CppMethodIntialized = true;
}
int32_t V_0 = 0;
int32_t V_1 = 0;
Object_t * V_2 = {0};
{
Object_t * L_0 = ___key;
if (L_0)
{
goto IL_0016;
}
}
{
ArgumentNullException_t1_1500 * L_1 = (ArgumentNullException_t1_1500 *)il2cpp_codegen_object_new (ArgumentNullException_t1_1500_il2cpp_TypeInfo_var);
ArgumentNullException__ctor_m1_13269(L_1, (String_t*)_stringLiteral793, /*hidden argument*/NULL);
il2cpp_codegen_raise_exception((Il2CppCodeGenException*)L_1);
}
IL_0016:
{
Object_t* L_2 = (Object_t*)(__this->___hcp_12);
Object_t * L_3 = ___key;
NullCheck((Object_t*)L_2);
//LINE 8481 HERE !!!! - CRASH
int32_t L_4 = (int32_t)InterfaceFuncInvoker1< int32_t, Object_t * >::Invoke(1 /* System.Int32 System.Collections.Generic.IEqualityComparer`1<System.Object>::GetHashCode(T) */, IL2CPP_RGCTX_DATA(InitializedTypeInfo(method->declaring_type)->rgctx_data, 35), (Object_t*)L_2, (Object_t *)L_3);
V_0 = (int32_t)((int32_t)((int32_t)L_4|(int32_t)((int32_t)-2147483648)));
Int32U5BU5D_t1_275* L_5 = (Int32U5BU5D_t1_275*)(__this->___table_4);
int32_t L_6 = V_0;
Int32U5BU5D_t1_275* L_7 = (Int32U5BU5D_t1_275*)(__this->___table_4);
NullCheck(L_7);
NullCheck(L_5);
IL2CPP_ARRAY_BOUNDS_CHECK(L_5, ((int32_t)((int32_t)((int32_t)((int32_t)L_6&(int32_t)((int32_t)2147483647)))%(int32_t)(((int32_t)((int32_t)(((Array_t *)L_7)->max_length)))))));
int32_t L_8 = ((int32_t)((int32_t)((int32_t)((int32_t)L_6&(int32_t)((int32_t)2147483647)))%(int32_t)(((int32_t)((int32_t)(((Array_t *)L_7)->max_length))))));
V_1 = (int32_t)((int32_t)((int32_t)(*(int32_t*)(int32_t*)SZArrayLdElema(L_5, L_8, sizeof(int32_t)))-(int32_t)1));
goto IL_00a2;
}
IL_0048:
{
LinkU5BU5D_t1_3010* L_9 = (LinkU5BU5D_t1_3010*)(__this->___linkSlots_5);
int32_t L_10 = V_1;
NullCheck(L_9);
IL2CPP_ARRAY_BOUNDS_CHECK(L_9, L_10);
int32_t L_11 = (int32_t)(((Link_t1_256 *)(Link_t1_256 *)SZArrayLdElema(L_9, L_10, sizeof(Link_t1_256 )))->___HashCode_0);
int32_t L_12 = V_0;
if ((!(((uint32_t)L_11) == ((uint32_t)L_12))))
{
goto IL_0090;
}
}
{
Object_t* L_13 = (Object_t*)(__this->___hcp_12);
ObjectU5BU5D_t1_272* L_14 = (ObjectU5BU5D_t1_272*)(__this->___keySlots_6);
int32_t L_15 = V_1;
NullCheck(L_14);
IL2CPP_ARRAY_BOUNDS_CHECK(L_14, L_15);
int32_t L_16 = L_15;
Object_t * L_17 = ___key;
NullCheck((Object_t*)L_13);
bool L_18 = (bool)InterfaceFuncInvoker2< bool, Object_t *, Object_t * >::Invoke(0 /* System.Boolean System.Collections.Generic.IEqualityComparer`1<System.Object>::Equals(T,T) */, IL2CPP_RGCTX_DATA(InitializedTypeInfo(method->declaring_type)->rgctx_data, 35), (Object_t*)L_13, (Object_t *)(*(Object_t **)(Object_t **)SZArrayLdElema(L_14, L_16, sizeof(Object_t *))), (Object_t *)L_17);
if (!L_18)
{
goto IL_0090;
}
}
{
Object_t ** L_19 = ___value;
ObjectU5BU5D_t1_272* L_20 = (ObjectU5BU5D_t1_272*)(__this->___valueSlots_7);
int32_t L_21 = V_1;
NullCheck(L_20);
IL2CPP_ARRAY_BOUNDS_CHECK(L_20, L_21);
int32_t L_22 = L_21;
(*(Object_t **)L_19) = (*(Object_t **)(Object_t **)SZArrayLdElema(L_20, L_22, sizeof(Object_t *)));
return 1;
}
IL_0090:
{
LinkU5BU5D_t1_3010* L_23 = (LinkU5BU5D_t1_3010*)(__this->___linkSlots_5);
int32_t L_24 = V_1;
NullCheck(L_23);
IL2CPP_ARRAY_BOUNDS_CHECK(L_23, L_24);
int32_t L_25 = (int32_t)(((Link_t1_256 *)(Link_t1_256 *)SZArrayLdElema(L_23, L_24, sizeof(Link_t1_256 )))->___Next_1);
V_1 = (int32_t)L_25;
}
IL_00a2:
{
int32_t L_26 = V_1;
if ((!(((uint32_t)L_26) == ((uint32_t)(-1)))))
{
goto IL_0048;
}
}
{
Object_t ** L_27 = ___value;
Initobj (Object_t_il2cpp_TypeInfo_var, (&V_2));
Object_t * L_28 = V_2;
(*(Object_t **)L_27) = L_28;
return 0;
}
}