so, um, i got a new mouse, i plugged it in, i checked vegas pro 16, and it no longer works, i get error code -59(i have no idea if the mouse has something to do with it) i also don't know how to register my product if that helps(i cant find the serial number)
See if this Vegas support article re Error 59 helps:
At the bottom of the article is an Ask Support link to lodge a support ticket with MAGIX.
Also, use the forum's search facility using the keywords Error 59 - there are lots of previous posts and comments about this error which may provide you with help.
It's unlikely that the mouse has anything to do with error 59.
Since you have already been using Vegas Pro 16 (because you say that it no longer works), your serial number for VP16 should be easily available on your MAGIX My Account under the My Products heading. If you bought VP16 from MAGIX, the serial number for it will be on the purchase confirmation email that you would have received from MAGIX at the time of purchase.
Not clear what you mean by VP16 no longer works. Are you able to open VP16 at all? If so, you should find your serial number by clicking through "Help" then "About" from the menu bar.
Cheers, Robbie