Observed with linux machine trying to connect to another linux machine with xrdp installed.
[ozgur@ozgur ~]$ rdesktop -u <USERNAME> -p <PASSWORD> <IP>
Connection established using plain RDP.
Clipboard(error): xclip_handle_SelectionNotify(), XGetWindowProperty failed
Clipboard(error): xclip_handle_SelectionNotify(), unable to find a textual target to satisfy RDP clipboard text request
Clipboard(error): xclip_handle_SelectionNotify(), XGetWindowProperty failed