I have High Sierra installed from a USB bootable drive on a Samsung SSD (Samsung MZ-76E500B/EU 500 GB 860 EVO Sata III 64L V NAND Solid State Drive) but I need XCode and that needs to be on Mojave 10.14.4+ and because i have a third party SSD the app store blocks me from upgrading.
So I put a Catalina beta on a USB drive but when I load up the iMac holding option and select the drive I just get a cancel symbol.
Not sure what to do to get a more modern OS on this SSD? Anyone had any luck with Mojave or will that be the same?
Thanks in advance