There are times where the default settings from the servicemanager might be needed.
You can remove the uc4.smd file that you were working on at the time that had incorrect entries and then copy the uc4.ori.smd file to uc4.smd and you'll have the defaults again. The uc4.ori.smd file can always be found on the image or by downloading the latest image where it is in the \Automation.Platform\ServiceManager\windows\x64\ folder