主题：附件错误

 请问以下代码第一次运行正常，后面运行出现下图错误，请问是什么原因？进程找不到

    Dim Book As New XLS.Book(ProjectPath & "Attachments\样品单.xls")
    Dim fl As String = ProjectPath & "Reports\样品单.xls"
    Book.Build()
    Book.Save(fl)

'通过邮件发送
Dim m As New MailSender
m.Host = "192.168.1.89"
m.Account = "xiaoliu"
m.Password = "xiaoliu1234567"
m.From = "liss@great.com"
m.To = "liss@great.com"
m.Title = "订单上报"
m.C
m.AddAttachments(ProjectPath & "Reports\样品单.xls")
m.SendAsync()

此主题相关图片如下：1.png