xfce issue

[Mohammad BadieZadegan]

Hi dear OpenBSD users.
I installed OpenBSD and then XFCE on multiple computers but on a computer
while I startx , it runs XFCE but every clickable icons such as terminal or
browsers or ... does not running anything!
On the other computers XFCE runs OK but a computer don't running any icons!
How can I resolve this issue?
Thanks in advance.