Can't activate selective sync on my Windows machine

I just bought a new laptop and tried to set up a selective sync for some of my folders.

But for some reason, it just doesn't work. I keep getting the same error while selecting folders.

Here's what happens (the interface is in Ukrainian, but you'll get the logic): 

This is a welcome page after installing Dropbox where it offers me a selective sync.

 

Here, I select the folders that I want to sync.

 

And here's the error I get. Saying "Unfortunately, it didn't work. Press Select Folders and try again".

I tried several times, selecting different folders, reinstalling dropbox, choosing another drive for my dropbox folder, rebooting PC, but nothing. Dropbox is allowed in my default windows firewall. But I also tried disabling the antivirus and firewall, also nothing.

Ignoring the error and setting selective sync later also doesn't help. Dropbox just stuck at constant indexation and never syncs my files no matter what folder I choose.

 

I checked dropbox on my main PC and it works fine. Folders and files syncing without any issues. The issue may be the laptop itself, but I don't know what exactly.

Please help 🙂 Thanks.