When I opened and saved the attached presentation, text on the first slide in resulting presentation became bold as you can see on the attached screenshot.
I have worked with the presentation file shared by you and have not been able to load the presentation even using the latest version on my end. An issue with ID SLIDESJAVA-35109 has been created as regression 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 automatically notified once the issue will be fixed.