_declspec(dllexport) void TestArray(wchar_t** OutBuff,int Count,int MaxLength)
{
    for(int i=0;i<Count;i++)
    {
        wchar_t buff[25];
        _itow(i,buff,10);
        wcsncpy(OutBuff[i],buff,MaxLength);
    }
}

class Program
    {
        [DllImport("Native.dll", EntryPoint = "?TestArray@@YAXPAPA_WHH@Z", CharSet = CharSet.Unicode, CallingConvention = CallingConvention.Cdecl)]
        private static extern void TestArray([MarshalAs(UnmanagedType.LPArray)]
        IntPtr[] OutBuff, int Count, int MaxLength);

        static void Main(string[] args)
        {
            int count = 10;
            int maxLen = 50;
            IntPtr[] buffer = new IntPtr[maxLen];
            for (int i = 0; i < count; i++)
                buffer[i] = Marshal.AllocHGlobal(maxLen);

            TestArray(buffer, count, maxLen);

            string[] output = new string[count];
            for (int i = 0; i < count; i++)
            {
                output[i] = Marshal.PtrToStringUni(buffer[i]);
                Marshal.FreeHGlobal(buffer[i]); // crash is here, when count is 1
                Console.WriteLine(output[i]);
            }

            Console.ReadKey();
        }
    }
}

IntPtr[] buffer = new IntPtr[count];   // NOTE: not maxLen
        for (int i = 0; i < count; i++)
            buffer[i] = Marshal.AllocHGlobal(maxLen * sizeof(Char));