Kate,
I'm not aware of any issues here. We will try to test though have not been able to yet.
I'll get myself set up and then attempt to replicate, but can you please in the interim A) provide me with the messaging from the error message and B) if there's no private information (Or if you can create a quick test file) send me a .pptx file that you're having the issue with and we'll test using that as well.
Please also in the meantime can you kindly confirm the files you're having the issue with are saved as .pptx files and in an accessible file location? Can you also please try to save the pptx file to your desktop and attempt to replicate the issue?
I've logged this against case 253582, please let us know your results. Thank you,