The problem with the appearance of files in the SandBox

I take the file and copy it to VTRoot in the right folder in real OS, but the SB-program cannot access it. App sees this file, but cannot open it “access denied”. Why?

Is this some kind of protection? I want to restore VTRoot folder, but most of the files cannot be opened in SB-programs.

But this problem is not with all files. Sometimes I copy files and work normally.