For a visual walkthrough on resetting the license server and resolving activation conflicts, check out this guide:
The most common cause of "Error 6" is a lack of administrative privileges. The activator needs to modify system registry keys and install services that standard user accounts cannot access. Locate the SolidWorks.2017.Activator-SSQ.exe file. the file and select Run as Administrator . Solidworks.2017.activator-ssq Error 6