I bought a Maschine Mikro MK3 in a flea market, I don't have proof of purchase, and no way to contact the seller, what should I do?
@AXVRAI You can always contact our support to see what's possible: https://bit.ly/NI_Support_All
You could just buy the Maschine 3 software.
It'll still ned to be registrered with NI, won't it?
https://support.native-instruments.com/hc/en-us/articles/360001301669-My-Serial-Is-Already-Registered-to-Another-User-Account
The serial number registration is primarily so any software that normally ships with the product can be accessed by the new owner - but as you can just buy Maschine 3 anyway, it's not essential.