How to transfer backed up library back to roon

For reasons that I cannot explain roon went off-line and when I rebooted roon, my playlists were missing. (Albums and artists etc are still available)I had previously backed up the room library according to the user guide but now I am having difficultly transferring the backed up library back to roon . Any help would be appreciated

On what machine is your server running (Mac/PC/Linux)?

Did you read the article in the KB:
How do I move my Roon library to a new computer?

I know you are not moving your library, but this article also explains where the database is located and different platforms and what needs to be copied.

Chris, thanks for your message.
I’m using an iMac.
I read the KB article and a lot of it is way over my head. I am a music lover but not a computer expert. Unfortunately it appears that roon may require the latter
I have posted other pleas for help in the support section of the roon community. I hope I can get an answer that I understand because I have spent countless hours building up my playlists
Thanks for your patience

Let me suggest that someone take this topic “how to move a library to another computer” copy it and create a new FAQ by modifying the copy to describe “how to discover a lost library on the same core computer and transfer it back to roon”
I did not lose my complete library but I did lose my playlists as I have described in a posting I made yesterday