@serhatgulmez,
Thanks for your query.
Well, the Dlls package for Aspose.Total for .NET is updated once in a while, so it might have older API versions in it. We always recommend our users to download/get their desired latest .NET APIs (versions) by browsing their individual nodes (in Downloads section) or get these from Nuget repos. For example, you may download/get latest version for Aspose.Words, Aspose.Cells, Aspose.PDF, Aspose.Slides, Aspose.Email, etc., by navigating to the following pages:
https://downloads.aspose.com/words/net
https://downloads.aspose.com/cells/net
https://downloads.aspose.com/pdf/net
https://downloads.aspose.com/slides/net
https://downloads.aspose.com/email/net
Hope, this helps a bit.