When using a custom skin and setting the EnableEmbeddedSkins="true", I get an error:
Telerik.Web.UI.RadGrid with ID='g' was unable to find embedded skin with name 'Custom'. Please, make sure that you spelled the skin name correctly, or if you want to use a custom skin, set EnableEmbeddedSkins=false.
Do we have to use a specific name for our skin? It seems like your suggestion is contradicting the suggestion in the error message.
All other images work fine in my grid. Only the ExpandImage and CollapseImage are missing.