Apple’s most meaningful communication about this inexcusable failure of support were the 404 errors from its download pages.
security
How to check whether any Installer package or app has valid certificates, using this new version of Taccy.
Validating signatures isn’t straightforward. GUI apps are limited, and command tools confusing and prone to user error.
Its very convenient and quick to transfer files between Macs, but also sets the quarantine flag on everything it transfers. This can cause problems.
In the last day or so, rumours have spread about the appearance of macOS Catalina 10.15 Supplemental Update […]
Do you use third-party command tools? Are you using or planning to use Catalina? This explains how 10.15 changes first run checks on those tools, and their effect on all users.
Why third-party kernel extensions may have problems working in Catalina, and whether those KEXTs will become SEXTs.
Important updates if you’re running Catalina, as they add the KEXT blocker back into their checks.
Don’t rely on being able to use any Apple installer package unless it has been downloaded recently: its certificate is about to expire.
Details of their locations, purposes, and the current installed version. These have changed a great deal since Mojave.
The Eclectic Light Company 