Hi Dan, and welcome to the E-Learning Heroes Community! So happy you're here! 🥳
Thanks so much for reaching out! I'm sorry to hear you're having this issue importing PowerPoint Presentations into Storyline 360.
For our System Requirements, we require Microsoft Office 365 (desktop apps only) or the latest perpetual version of Microsoft PowerPoint (32-bit or 64-bit). Could you please confirm your versioning?
Also, do you happen to have a screenshot of the error message you are seeing? It sounds like you meant to attach something, and I'm not seeing it in your original post.
I'd like to pass along this article that can help us get to the bottom of this issue:
(Perhaps one of the workarounds (Password Protection, Double-Checking versioning, Security Permissions, etc.) suggested in this article will be helpful.)
I'm looking forward to hearing from you!