I did dnn setup on local machine. It has below url localhost/tbregistrylocal/
on local set up its not showing any error for host skin. setup has default skin Gravity.
but when i upload set up on server its showing error couldnt load skin
I try to change skin of host but not able to change.
Error is coming because it looking for local folder tbregistrylocal
it shoudnot take this path /tbregistrylocal/Portals/_default/Skins/Gravity/2-Col.ascx,
path should be like /Portals/_default/Skins/Gravity/2-Col.ascx,
why its happening 
please find below screen shot