Make sure you update your serial to usb adapters as you update pc to Windows 10 and 11.
The old Prolific adapters will not work. Recycle them
Buy modern ones for your timer to PC cables and scoreboard out cables.
We like the Sabrent model
Split Second recommends the same one
ALWAYS check your adapters in Windows Device Manager. Right click on the lower left Windows flag. Scroll up and click Device Manager. Or click on the ambulance in the upper right of Split Second Setup and Test
Go to ports and remove the adapter. The "COM" number should disappear after refresh. Plug it back in and it will reappear. Repeat for all.
If your don't see it in device manager it does not exist!