When using stand-alone ImageManager I keep getting the message:
Telerik.Web.UI.RadUpload with ID='upload1' was unable to find an embedded skin with the name 'Material'. Please, make sure that the skin name is spelled correctly and that you have added a reference to the Telerik.Web.UI.Skins.dll assembly in your project. If you want to use a custom skin, set EnableEmbeddedSkins=false.
I am using Material skin, but obviously the obsolete RadUpload is stille used there?
I use LightWeight rendering but still get the message:
imageManager.Parameters("RenderMode") = Telerik.Web.UI.RenderMode.Lightweight