Open the demo at https://demos.telerik.com/aspnet-mvc/filemanager

right click Images in the tree and click rename. 

Change the name

select the new folder name in the tree

try to do anything with the files in that folder (rename or delete are available in the demo)

= server error 500 

the path did not update to the new path.

but if you refresh you see the folder renamed and worked (and now you can do things with the files inside)

now if you add a folder inside Images and do the same process over again it works as expected...