DateTime.ParseExact 在日语中抛出 System.FormatException

问：

我有以下抛出System.FormatException的代码。异常消息已本地化为日语，因此我怀疑这可能是由于计算机上的某些本地设置造成的。任何可能导致该问题的建议？

下面是简化代码：

 string format = "yyyy-MM-dd HH-mm-ss";

            using (var stream = new FileStream(@"...\New Text Document.xml", FileMode.OpenOrCreate, FileAccess.ReadWrite))
            {
                stream.Seek(0, SeekOrigin.Begin);
                stream.SetLength(0);

                var test = new Test();
                test.AccessDateTime = DateTime.Now.ToString(format);
                
                DataContractSerializer serializer = new DataContractSerializer(typeof(Test));
                var settings = new XmlWriterSettings { Indent = true };
                using (var w = XmlWriter.Create(stream, settings))
                {
                    serializer.WriteObject(w, openFiles);
                }
            }

            DateTime d;
            using (var stream = new FileStream(@"...\New Text Document.xml", FileMode.OpenOrCreate, FileAccess.ReadWrite))
            {
                XmlDictionaryReader reader = XmlDictionaryReader.CreateTextReader(stream, new XmlDictionaryReaderQuotas());
                DataContractSerializer serializer = new DataContractSerializer(typeof(Test));
                Test test = (Test)serializer.ReadObject(reader, true);

                d = DateTime.ParseExact(test.AccessDateTime, format, CultureInfo.InvariantCulture);
            }


       [DataContract(Name = "Test")]
        public class Test
        {
            [DataMember(Name = "AccessDateTime")]
            public string AccessDateTime { get; set; }
        }

迄今为止，我试图传递日本文化。ToString（..） 方法，但一切按预期工作，ParseExact 工作正常。