解析时无法将字符串识别为有效的DateTime

因此，我有一些代码将当前的DateTime写入txt文件，然后发布一些嵌入（如果txt文件不存在）。如果是的话，它将读取文件，检查文件中的日期是否在1分钟前，如果是，它应该发送与创建文件的日期相同的嵌入，如果还没有1分钟，那么它将发送一个嵌入消息，告诉您等待。

由于某种原因，创建和发送方面可以正常工作，但是如果我再次运行该命令，则当它尝试将字符串转换为DateTime时，它将失败，并说“字符串未被识别为有效的DateTime”。我已经检查了多个网站，并且我使用的日期时间格式正确。有任何想法吗？

string FilePath22 = Environment.CurrentDirectory + "/servers/" + Context.Guild.Id + ".txt";
string FilePath = Environment.CurrentDirectory + "/descriptions/" + Context.Guild.Id + ".txt";
string FilePath2 = Environment.CurrentDirectory + "/invites/" + Context.Guild.Id + ".txt";
var chnl = Context.Client.GetChannel(511281184760791056) as ITextChannel;
string invitelink = System.IO.File.ReadAllText(FilePath2);
string desclink = System.IO.File.ReadAllText(FilePath);
var builder2 = new EmbedBuilder()
        .WithColor(Color.Orange)
        .WithAuthor(Context.Guild.Name)
        .WithThumbnailUrl(Context.Guild.IconUrl)
        .WithUrl(invitelink)
        .AddField("Information", "**Owner:** " + Context.Guild.Owner + Environment.NewLine +
        "**Description:** " + Environment.NewLine + Environment.NewLine + desclink + Environment.NewLine + Environment.NewLine + "**Invite:** " + invitelink)
        .AddField("Other Info", "**Members:** " + Context.Guild.MemberCount + Environment.NewLine + "**Emotes:** " + Context.Guild.Emotes.Count + Environment.NewLine + "**Roles:** " + Context.Guild.Roles.Count + Environment.NewLine + "**Created At:** " + Context.Guild.CreatedAt.Date);
        var embed2 = builder2.Build();
        await chnl.SendMessageAsync(embed: embed2);
        var builder44 = new EmbedBuilder()
        .WithColor(Color.Orange)
        .WithTitle("Server Bumped!");
var embed44 = builder44.Build();

if (!File.Exists(FilePath22))
{
    await ReplyAsync(embed: embed44);
    System.IO.File.WriteAllText(FilePath22, DateTime.Now.ToString("MM/dd/yyyy HH:mm:ss", CultureInfo.InvariantCulture));
    return;
}

string readit = System.IO.File.ReadAllText(FilePath22);
Console.WriteLine(readit);
var converted = DateTime.Parse(readit); //problem
Console.WriteLine(converted);
if (HoursPassed(converted))
{
    await ReplyAsync(embed: embed44);
    System.IO.File.WriteAllText(FilePath22, DateTime.Now.ToString("MM/dd/yyyy HH:mm:ss", CultureInfo.InvariantCulture));
    return;
}

var builder10 = new EmbedBuilder()
        .WithColor(Color.Orange)
        .WithTitle("You must wait 24 hours before bumping your server! Try again later.");
var embed10 = builder10.Build();
await ReplyAsync(embed: embed10);