Thank you for writing.
We are aware of the reported issue. It is logged on our feedback portal, here:
FIX. RadRichTextEditor - when the document is printed there is a blank space on the bottom of the page
. You can subscribe to it and be updated when its status changes. The issue has been investigated preliminary and it turns out to be quite complex. For the time being there is no suitable workaround.
Let me know if you have other questions.