Using the latest 2022.3.1109.45, our web application is catching "Invalid Resource Request" exceptions when the Windows7 or Vista (maybe others too) loads the "Editor" control in "Classic" mode.    By decoding the URL, the control is having problems locating the image below

WebResource.axd?d=ZHkUja8e5EF7zNoz8IiY_kAGH7MBQgCnq0BEYT2AtFLv57GDfGbEymwRG8H68WuiE_6l2fpZpqb_FzVc_OItknX-LMTzvQOwC0Mk8HaCtGvNzWl-5nNlZ6xpbOjNSk4A0QtPGtyV0UA-BWX4bOfPU8EI30eAVg8UO6p7yERiuEbCUoiZOGUevYGPdrNVvPel0&t=638034624000000000
Error Message: This is an invalid webresource request.

Telerik.Web.UI.Skins|Telerik.Web.UI.Skins.Vista.Editor.ToolbarVerticalSprites.gif

Telerik.Web.UI.Skins|Telerik.Web.UI.Skins.Windows7.Editor.ToolbarSprites.gif

Change the skin of the radeditor in the default.aspx to another skin such as "metro" and the problem will not happen.    It works OK at least on Black, Metro and Silk but haven't tested others, you can tell it doesn't work when the divider bars in the editor toolbar don't appear properly.