reinstallation mathcad 15 on a new pc with a single user license

Hello,

I try to install and open Mathcad 15 on a new PC and when i try to start the mathcad exe, i get an error message that is in german and i propably cant translate it 1:1 but it says something like "the requested license contains an error. invalid host / the hostid of this system does not match the hostid specified in the license file...".

I downloaded the setup and installed mathcad with it multiple times because i wanted mathcad on my 2nd drive thats not the c drive with windows on it but even with custom installation selected in the installer, it installed mathcad always on the c drive and i shifted the license file around a few times aswell and tried opening mathcad during mulitple iterations of this process. I thought i mention that in case that might throw things off or corrupt the linces file or whatever. I deleted and reinstalled the license file aswell naturally.

And also, if i am on the website and press on the top left corner, select "manage and monitor software" and press on "download software" --> "order or download software updates" --> "mathcad" --> any mathcad version --> "most recent datecode" it always says "0 date codes for xxxx / Datecode xxxx / Not available" so i cant download it anymore, i used a link that our university guy send us to download it from. I dont know whats up with that but maybe that helps with solving my license problem in some way.