Missing files after syncing with Windows client

Today I installed the windows client for my Nextcloud.
It took a while to have it synced but after some time it was done.
While the syncing was going on I recognized that my router (fritzbox) was having problems (restarted 3 times)
Now I’m checking my files and my heart stopped…a lot of files are missing now. They are not on my windows client nor on my nextcloud server.
Some folders are empty and some folders are missing. My wif will kill me if I tell her that the pics from our daughter are gone.

Please, I need help!!! Is there something like versioning of folders so I can return to a version from yesterday?

I’m a noob with nextcloud! Hope you can help me

I’m running Nextcloud 16.0.5 on my Synology.

Thanks a lot

Okay, master question… what’s your backup of your nextcloud instance? You do have a backup, right? NC is not a backup solution, it’s a file-sync one. Did you have a look at the trash can (lower right in the NC web client) to see, if your files are still in the trash?

2nd question, when you setup your windows nextcloud client, did you opt for a clean sync? That would clean up the data folder of your user on your NC instance.

Thanks for your response.
I don’t have a backup of my NC because I use it to store my backups of my PCs.
I did not use the CLEAN SYNC option.
The bin folders have already been checked and nothing there. I also couldn’t find any DELETING messages in the activities.

Well, that’s bad, indeed. Did you, by any chance, already had installed the NC client on that particular PC before? If yes, it could be that this caused this issue, if there’d be any leftovers from the local databases, which the NC client uses…

These forensics aside, have you checked your Synology for those missing files - e.g. use the search around in the NC data folder, if there’re any abandoned user folders? That would be my last advice. Failling that, I’d consider these files lost.

Or maybe, the Synology has some kind of Auto-Snapshot…