1) Windows 10 with the latest Updates.
2) Acutally Fences Version
I have fixed the Problem.
If you are running Fences with Drop Down Windows and install Deskscape and activate it, Fences can´t fix the Issue alone.
I must delete all my Fences Drop Down Windows and create new ons. And then I must put the Icons in it again.
Then it is running.
If I change my Background with Deskscape I have no Problems.
I think the Problem is, that Fences is fixed in one Desktop Mode. If you install Deskscape it will be an other Mode from DeskScape.
After the first Installation from Deskscape I have seen all my Icons from Fences. I was going about my Fenses Drop Down Window.
In the Background I could see the Shadow from the scrolling down Window. If I was going back, the Window scrolls up, but the Icons will be there and I can show it.
What I mean is, the Icons have the right Position, but not in the Drop Down Window. You can´t put it in it. You must delete it at the first Step and create a new one. Then you can copy it in the new Drop Down Drawer.
In the Preferences from Fences I have activate, that the Drawer should close, if it´s pined on the Top from the Desktop.
But it has no Function after Installation from Deskscape.
eTo fix this Issue you must go to the Drawer Preferences and activate in Point "View" -> "Fold Fences"
Then all is OK.