Beatgrid lines gone after backup restore

Here is a picture of the situation: https://imgur.com/a/bltzl

Chances are one of the database folders is also missing or damaged, or the database simply isn't pointing to the right path. If you try and import / analyse a new track, does it keep the grid, or warn you that it can't use the existing path?

Thanks for the quick reply. I've tried analyzing a few tracks. A pop up screen with 'analysis setting' appears with the warning that analyzed information will be overwritten. After analysis the grid is back but it's not the one I configured. Is it possible to restore the database folder?

Before you rush into that, what I'm asking is if a newly imported track gets a beat grid?

And what exactly did you do when you "removed your collection" from rekordbox? What files / folders did you delete?

Newly imported tracks do get a beat grid. 

What I did was, I was in my 'collection' folder and pressed 'delete' on my keyboard. I was under the assumption that I was in my playlist folder and was simply deleting all tracks from my playlist (I do this sometimes so that I can add my whole collection with new tracks + adjustments to old and new tracks to my playlist), but unfortunately this was not the case.

Okay, so when you did that, you deleted the tracks from the collection -- and that also removed the corresponding data files with the beat grids, so when you restored the database from the .backup.edb file, it only restored the entries in the collection, not the other files. You'll have to either restore a backup of those files (from TimeMachine, etc) or re-analyse them.

Unfortunately I'll have to re-analyze my whole collection then. Not the end of the world, at least I didn't lose my actual files. Will take me a couple of hours to re-analyze and reset the beat grids. :) Thanks anyway for the support, much appreciated.

Can I suggest in a following update of Rekordbox to be able to restore the beat grid as well? Or is this not an easy process. Or, when in the 'collection' folder, have Rekordbox ask to confirm when pressing delete? I would think this to be a simple solution when accidentally hitting the wrong key or, like me, assuming you are in the playlist folder.

I think a more reasonable suggestion would be to consider keeping proper backups. ;) Try a system like Backblaze, or even just making a regular backup (export).

Having an "undo" is something we're still hoping can be implemented (it's on the list), but I feel having an alert warn me every time I delete a song would be more of a nuisance than a help.

Well yes, I will consider back ups from now on ;) but it would be user-friendly if there was an option in preferences for a delete confirmation prompt. Then let the user decide if this is useful or not :) An undo button would be great. Just discovered the analysis lock option too. Will see how that works out for me.

What happens if you do a backup restore and did not delete anything, but are still having the same issue? I moved both my rekorbox xml master playlist and itunes folder off hard drive. Resyncing iTunes wasnt a problem but that rekordbox masterplaylist3 xml says it can't read it.