"Media offline" problems, please help!

Hi, I am encountering a frequent issue with DaVinci resolve and I don't know how to fix it. Essentially, I'll work on a project for a while, I make sure I save it, then I close it down for the time being. When I open up the project again, later, some clips (not all) say "media offline" and I cannot view the clips, although the audio is still clear and remains as it was before. When I export the project, that same section simply says "media offline".

I don't know why it does this, or how to fix it.

Details: My videos are around 10-20 minutes. I have encountered this issue with every project. The only solution I have is to delete the project and edit it all again, but then I waste hours of time.

I work on a mac and have the regular version of DaVinci Resolve.
I make sure I save the files every time.
I drop files straight from finder into the media pool
Not every file says "media offline"

Please help, I'm trying to upload a YouTube video, but a large portion of my project says "Media offline" in red, and I don't want to edit the video again as it took hours already. Thanks

I'm having the exact same issue, there is 1 clip that always shows Media Offline, no matter how I import it, but I can hear the sound clearly and last time I rendered a sample it was still there.

I deleted all my cache as well just to be sure, all other files from the same folder load without any issues.

By going through a myriad of topics on this, it seems that there is an issue with the HECV encoder, my footage is from a gopro at 60FPS, which makes it HECV encoded. Looks like windows updates, or the latest version of DR broke support for it.