: Leftover registry entries from older SolidWorks versions conflict with the 2018 licensing script.
Don't scatter your installation files. Keep the original SSQ activator folder and its contents in a dedicated, easily accessible location on your C: drive. This ensures the activator can find all its necessary files when you run it. solidworks 2018 activator ssq error 6
Re-extract your activator files from their original archive, as your previous attempt likely resulted in missing files. 2. Completely Purge Legacy SolidWorks Registry Keys : Leftover registry entries from older SolidWorks versions
Ensure your system date and time are correct. You can force a sync with internet time servers: solidworks 2018 activator ssq error 6
Right-click and any residual SolidWorks folders if you are attempting a completely fresh installation.