NullReferenceException save presentation properly (C# .NET Core)

Hi there. I can’t open and save presentation properly due to NullReferenceException. The sample project is here:
https://drive.google.com/open?id=110SFlPEdCcpKP8Ig2t9_85YRLmcU5X3t
Could you advise?

@obrusentsov,

I have worked with the sample file shared by you and have been able to observe the issue specified. A ticket with ID SLIDESNET-41981 has been created in our issue tracking system to further investigate and resolve the issue. This thread has been linked with the issue so that you may be notified once the issue will be fixed.

The issues you have found earlier (filed as SLIDESNET-41981) have been fixed in this update.