Follow these steps :

Delete the C:\wsession and C:\Program Files (x86)\RDPlus folder and try again.

If this does not work then follow this procedure :

  1. Open a control panel and manually uninstall the Universal printer. 
  2. Make sure no users are connected, then uninstall RDPlus, reboot your computer.

If these steps did not work then download and install a fresh setup before restarting above procedure : 
https://rdplus.com.au/download/

I recommended you also to deactivate your antivirus before installing/uninstalling RDPlus