Mathcad 12 will not start

I purchased and installed Mathcad Prime 12. However, I now understand that, because I am using a Dutch Windows 11 OS, Mathcad does not start. First of all, I find it unbelievable that PTC does not mention this very clearly beforehand, but that you are only confronted with this after purchasing. What really makes matters worse is that, although you start from and with the English website, you are redirected during the installation process to a Korean website, which is unreadable. So now I am stuck with a Mathcad version that I paid for and for which the 1-year period has already started, but which I cannot use. I would like this situation to be resolved ASAP.