Comment 6 for bug 1879385

After Dropbox is installed, it creates folder "{homedir}/Dropbox," and all files are synchronized from your dropbox account. So before it, there is no Dropbox folder in your home dir. I did not test it before Dropbox was installed, but I guess there will be no problem to star this file.

Now I checked my dropbox account; there is also feature to star files. Maybe there is a conflict between dropbox and nautilus star functionality.