Hey! Sorry for the inconvenience. I'm not sure what browser you're using, but some like Microsoft Edge can be really picky and make you jump through hoops to get the download to work.
Assuming you are on Edge, you need to click the three dots (...) in the download panel, click "Keep", click "Show more," and click "Keep anyway."
The reason this appears is because, at the moment, I am an individual developer and Microsoft requires an EV (Extended Validation) Code Signing certificate to bypass this screen. As well as the SmartScreen that comes up after the download. I do code sign MiniMeters with an OV certificate that is associated with my personal identity. You can check this once it is downloaded in the properties pane. I also have recently set up my LLC which should allow me to get an EV certificate soon to bypass those annoyances. Sorry again for the annoyance this causes.
Let me know if you need additional assistance.