will it be possible for me to use my maschine mk2 that I bought second hand at a thrift shop. The problem is I don’t know the owner.
You've already asked this question in another post three minutes ago. Why have you posted the same thing again?
I deleted the dupe.
Ask official NI support what are your options. To get things to speed up send them proof of purchase along with your questions.
The SW license cost for people in similar situations is around 75$ I think, that + whatever you paid for it makes it more expensive than buying a used MK2 with SW on ebay, so... yeah, pray they give you another option.
Just to cover any possible case, check at the bottom, to see its serial number.
Add that serial number manually in Native Access, just in case that have never registered, if you are lucky enough. Otherwise do as D-One instructed you.
Here is the full article of what you might need:
https://support.native-instruments.com/hc/en-us/articles/360001301669-My-Serial-Is-Already-Registered-to-Another-User-Account