Hi, Christian Muk
Welcome to the Microsoft Tech Community!
I understand that your question is about creating a PowerPoint presentation from a file.
First of all, I need to confirm the following information with you:
- Where did you choose to store the file? Are they stored locally or in OneDrive or SharePoint?
According to your description, the new document (Version 2409 Build 16.0.18025.20030) was tested, the selected file path is under the OneDrive path, and the test result is as shown below, which is able to operate normally, for reference:



Given this situation, it may be because PowerPoint requires the file to be located in your personal OneDrive in order for the conversion to work. Here are some suggestions to resolve this issue:
- Try to upload the files under the OneDrive path to see the result, if it is normal, move the problematic files to the OneDrive path and re-operate.
If the problem persists, then there may be an issue with the application itself and you can try the following steps:
- To try to repair Office, open the Control Panel, select Programs and Features, find Microsoft Office, right-click and select “Repair”.
If the above methods still can't solve your problem, please provide more details or screenshots so that we can help you further. Thank you for your understanding and cooperation! Please feel free to let us know if you have any other questions or need further assistance.
Cherry.Z|Microsoft Technical Support Specialist