MetroTouch "DragHandleDown.png" resource appears to be missing from 2015.1.225.40 version of Telerik.Web.UI.Skins.dll.

Got the following in my event logs:

Event message: An error occurred processing a web or script resource request. The requested resource 'pTelerik.Web.UI.Skins|Telerik.Web.UI.Skins.MetroTouch.Slider.DragHandleDown.png' does not exist or there was a problem loading it. 

Checked in the .dll for any reference to said resource. Found instances of "DragHandleDown.gif" for other skins (Black, Office2010Black, etc.) but nothing for MetroTouch.