Thank you for bringing this issue to our attention. I can confirm that this is a bug in the FileExplorer control and it is now logged into our bug tracking system for a further investigation. You can track its progress and vote in order to increase its priority here: feedback item
. Unfortunately there is no any workaround I can suggest you for the moment.
I have updated your Telerik points as a sign of gratitude for your report.
Check out the Telerik Platform - the only platform that combines a rich set of UI tools with powerful cloud services to develop web, hybrid and native mobile apps.