I have had Windows 8 Running Visilogic Software successfully for the past 6 Weeks. After an issue with our Domain we had our IT support company change Passwords and had to re-join notebooks to our Domain. Once we did this, we were unable to communicate with our Vision PLC's via Serial using Prolific USB-Serial Converter. We are using latest drivers and correct chip set. We have a Communications Driver Error (206). I have tried separate Windows 8 notebook with same result. I run Visilogic software as Administrator and same result. Software runs up fine but can not communicate. Have tried other cables and checked that worked on XP machine. Any Ideas.