It says on the Starter page that if you want to upgrade to Mini you just pay the difference. I can't seem to find where to do that on the website?
Yes, that is correct. Currently, we are finishing preparing a special upgrade form which will allow our customers to order upgrade keys. Meanwhile, we can simply give you a 50% discount for the MINI license.
Feel free to start a support ticket and I'll send you your coupon code. Thanks!
Then it's either an outdated root certificate or intermediate certificate problem. As an example, here is how the monitor driver properties window looks now on our test PC, RU version 18.104.22.168 downloaded from the site.