Solved XFCE does not show desktop

I installed xfce from ports with portmaster and the desktop shows black. Does anybody know why?
I installed vim, okular, chomium and then xfce successfully but this happened. I have nvidia drivers installed as well.
When I installed okular, firefox stopped working. So I installed chromium to keep going. It been difficult since I started to install packages but it's been all kind of dependencies problems, that I manage to use portmaster. With postmaster I had to install chomium or whatever application and then use portmaster, to upgrade it. Thank you for all. I'm a new user. Hope my comments help.
I solved it by installing this, xfce4-desktop-4.16.0.



2.Select Session and Startup

3.Select Application Autostart tab Add

5.On the window appeared enter name, description and

xfdesktop --replace

as command

6.Logout and Login again