If you recovered a Timeline, that Timeline may still be corrupted.
This happens. In the same project, create an new empty Timeline. Go to the Timeline you recovered. Lasso all of the clips and copy them to the clipboard. Then go to the newly created Timeline and paste them. I have done this many time to successfully recover files.
The clips were corrupted from the camera and would not play with VLC etc. I used an online service (at a cost) to recover the data. In the deliver page they play up to the end and then Resolve reports the error.
That is different. Not a Resolve problem. I have found VLC doesn’t offer much help in determining the usefulness of a video file. Media Player Classic, the last version they made, is much better. But, none of these can fix your problem.
I would try looking at one of the recovered clips with MediaInfo and/or ffprobe to see if you can find out what is wrong with the file. They can often be repaired with ffmpeg, but that is not something I can talk you through.
There are others on this forum much more qualified to help. Hopefully, you will get more help as others see your question.