Exception: ArgumentNullException on saving MSG to MHTML with RenderCalendarEvent (C# .NET)

The attached MSG calendar invitation opens in Outlook, but causes an exception in Aspose.Email 19.5 for .NET with the following code: input.zip (14.4 KB)

var message = Aspose.Email.Mapi.MapiMessage.FromFile("input.msg");         
var saveOpts = new Aspose.Email.MhtSaveOptions();  
saveOpts.MhtFormatOptions = Aspose.Email.MhtFormatOptions.RenderCalendarEvent | Aspose.Email.MhtFormatOptions.WriteHeader;
message.Save("output.mhtml", saveOpts);

The exception is:

System.ArgumentNullException
HResult=0x80004003
Message=Value cannot be null.
Parameter name: value
Source=mscorlib
StackTrace:
at System.String.IndexOf(String value, Int32 startIndex, Int32 count, StringComparison comparisonType)
at #=zfAI7bgSi9_djzK8FUMhyEZwR06kD.#=zQBoS0N2CR230(#=zb3OORIwMuvyO8vTqxT9567vJHOTF_Jzc2w== #=zXakRuCwd$96n)
at #=zfAI7bgSi9_djzK8FUMhyEZwR06kD.#=zNj$6G1rfxWr0(#=zpmyqBzD_IM1jr4lXvYLDfK8GIi$v #=zUdHVFZ4DoRSt3sXvLg==, MailMessage #=zN9TkzmE=)
at #=zfAI7bgSi9_djzK8FUMhyEZwR06kD.#=zCFT_vb4iW8GP(MailMessage #=zN9TkzmE=, MhtFormatOptions #=zfmo4h9Q=)
at #=zfAI7bgSi9_djzK8FUMhyEZwR06kD.#=zlnovW$s=(MailMessage #=zdmlwxbQ=, MhtFormatOptions #=zSMcH6TNhMICr)
at Aspose.Email.MailMessage.#=z2hB3MYs2nJ5f(MhtSaveOptions #=zGj$sPTPL_72O)
at Aspose.Email.MailMessage.Save(Stream stream, SaveOptions options)
at Aspose.Email.Mapi.MapiMessage.Save(Stream stream, SaveOptions options)
at Aspose.Email.Mapi.MapiMessage.Save(String fileName, SaveOptions options)

If I remove the 3rd line (saveOpts.MhtFormatOptions = Aspose.Email.MhtFormatOptions.RenderCalendarEvent | Aspose.Email.MhtFormatOptions.WriteHeader) it does not throw an exception, but then the MHTML file excludes the appointment information.

I want to be able to convert it to MHTML as a calendar event. Can you please advise if this is a bug in Aspose.Email and if so can it please be fixed, or otherwise how to avoid the exception?

Thank you!

@ast3,

I have worked with source file and have been able to observe issue. An issue with ID EMAILNET-39502 has been created in our issue tracking system to further investigate and resolve the issue. We will share good news with you as soon as the issue will be fixed.

Thank you for prompt response, Adnan! I will await an update.
Kind regards.

@ast3,

You are very welcome.

The issues you have found earlier (filed as EMAILNET-39502) have been fixed in this update.

I tested the update, and it has fixed the problem. Thank you!

@ast3,

Thank you for your feedback.