RekordBox Backup problem

I believe it’s encrypted which might be the reason you can’t open it. Good luck trying to get help from here though. Very little support.

They are not encrypted (or at least not always).

I'm having the same issue as OP, but have a little more insight on the topic. My previous RB Backups would produce normal ZIP files that I could browse through in Windows Explorer.

I know this isn't something that was changed at any point because I keep my library on an external drive which I also backup by copying the entirety onto a second of the same drive. I hadn't done that in a while and when I first noticed my Rekordbox Library backups were producing corrupt ZIP files, I connected to my other drive with its outdated database and did a Rekordbox backup on that, which produced a working ZIP files as before.

Unless there's some other factor that causes the ZIPs to sometimes be unreadable by file browsers, it appears to me that something happened within my collection/database that is causing Rekordbox to produce backup files that are unreadable ZIPs. In which case, it seems Rekordbox doesn't verify its backups. I assume the same or similar thing happened to OP.

I thought that when I converted my library over to RB 6, maybe it would repair whatever was the issue, but that is not the case.

I don't trust these backups, which is why I'm glad I have my full drive backup solution. But that takes hours. It would be nice if Pioneer could address this so I can do the faster backups (without copying the music) as interims in between the longer backups.