Unable to find an embedded skin with the name 'Windows7'

When I try to reach the parts which are built in webforms (I think… Warning for a very limited knowledge about webforms) like sales or “Search indices” under “System Settings” etc. I get the following error:

What can cause this issue? What should I look at?
This happend after I restored our test database with a new backup.

Litium version: 7.4.2

The actual DLL Telerik.Web.UI.Skins.dll is there?

No only Telerik.Web.UI.dll. I thought Litium.Studio.ThirdParty.Telerik would handle it?

Never mind, I needed to force the CD to restore all packages to make it work, I just don’t know why Telerik.Web.UI.Skins was gone. But it solved the problem anyhow. Thanks for your help Nils!

OK, great!

The Mvc project references Litium.Studio.Web that has dependencies for both of those Telerik libraries, but not sure either why they weren’t restored/added from the start.