Missing Frames and Drawings in an Imported Video Layer. Frames and drawings missing from Library too.

I imported an animatic and needed to use it for timing the animation, but when I opened the file today it was missing frames in the timeline, drawings in the library, and I checked the library file, elements, and the frames are missing from there too. It was not like this when I opened it up previously. What caused this and can I revert back to the scene file I had previously?

Troubleshoot 1.PNG

Troubleshoot 4.PNG

Was the project folder moved or renamed while the project was open and being edited in the software?
Was the project moved between media without having zipped/compressed the project folder first?

What exactly was done during the last edit session when the project was still intact?

Nothing was moved or renamed. I’m always sure to save anc close before I zip and make a back up. The only thing I did during the last session was work on the animation. I did not move or rename any layers in the project file.