Please help! I have been working on an extensive presentation (a virtual tour of a museum exhibition) and the inserted video files seem to disappear sometimes for no apparent reason.

The first time they disappeared, I assumed it was because I had accidentally opened the file in Powerpoint, which has been hostile to inserting these video files (I don't know why, they're in .wmv format) and could have stripped them out. I worked on it all day yesterday, including running the slideshow a few times, and closed it out, and then when I reopened it today, the videos are gone again.

Is this something anyone else has experience with? How can I keep the video files in place?

Version: 6.4.7.2 (x64) Build ID: 639b8ac485750d5696d7590a72ef1b496725cfb5 CPU threads: 8; OS: Windows 10.0 Build 22000; UI render: default; VCL: win; Locale: en-US (en_US); UI-Language: en-US Calc: CL

The file is a .pptx, as I initially created it in Powerpoint before realizing that PPT wouldn't let me insert the videos at all.

Edit: Fortunately I managed to figure out that the issue was likely the format. I saved as a .odp and it now seems to hold onto the video files after I save and exit. Adding this in in case someone else goes looking for a solution to the same problem later.