Can I keep my 2015 Office package and still properly activate through your methods? By reading the prompt I think that the problem may come from me having both. Should I risk uninstalling 2015 and be without any office?

PS: The last line reads: "Entry error: It's not possible to find the script file ..."
Edit: I installed and used Office 2019 no problem during a month with your methods. As of today, I was notified that I have two days left for the activation (I thought I did activated it, this bugs me off)