Hello,
There are a number of paths to take in terms of troubleshooting. You first might test with a tool like Putty (Download PuTTY - a free SSH and telnet client for Windows) connected to your Virtual COM port created by your USB dongle software. Turn Kepware off (Admin tool -> Stop runtime service). Then, initiate data flow from your scanner and see if it shows up in Putty's visual interface.
If it does, you have either a COM port binding issue - Kepware can't bind to your COM port for some reason, and you should check the Kepware Event log for confirmation of this - or you have a misconfiguration in your UCON transaction editor.
If you'd like any further assistance please send an email to presales.support@kepware.com. After the steps above, we'd want to organize a short remote support session to help further, and I will need you to engage my team and I through the email address provided.. You could also open a presales support ticket on PTC's eSupport portal: eSupport | PTC
Thanks ,
Sam