Description of problem:
this is a minor bug
If I set activity for any desktop apart.
KDE dont show wallpaper for same V. Desktop
Version-Release number of selected component (if applicable):
KDE dont show wallpaper
KDE corectly show wallpaper
I'm not sure I follow, but you're adding a new activity, right? If so, be aware that each activity can (and does) have it's own settings for background/wallpaper (ie, you can set a different one per activity).
It just so happens that the default wallpaper for additional activities (sometimes) ends up being blank, until you set one.
Is that what you're seeing?
OK, then set one, and everyone wins. :)