clips missing in sequences of old PP projects

[souven]

I opened a year-old Premiere Pro project today (iMac, Ventura 13.3) to locate some edited sequences for my documentary.  (I'm working in three different projects bc I have so much footage).  The sequences are there but when I put them in the timeline, most of the clips, both audio and video is missing.  Titles are mostly in tact, but withou the underlying footage.  It is not a relinking issue.  I first tried opening the project in version 23.5. Same thing in a version from 2022 (22.6.4).  2021 would not open the project.  The file was last saved in June 2022.  It is not the first time I have this trouble.  I am attaching screen shots of three timelines.