Cannot empty the clipboard error.

If you're having problems with copying contents on the fly, chances are your clipboard is already full. Search for the rdpclip.exe under the Processes of the Task Manager then end the task. This problem may have been brought by copying contents of the clipboard to and from the host and remote desktops. If you haven't found rdpclip.exe in your host PC, search for the file in the Task Manager of the remote desktop.