My current start-up drive runs 10.13.6. After a couple of system freezes involving full screen movies and VLC 3.0.6, I thought I'd refresh things by running the 10.13.6 combo update.

The dialogue box came up: "macOS High Sierra 10.13.6 Update can't be installed on this disk. This volume does not meet the requirements for this update."

I've run combo installers before over systems that don't actually update. Why not 10.13.6?

Thanks.

Oops. I've just thought of a possible reason: I have converted my SSD from APFS to HFS+ after the last upgrade. Could that be it?


iMac (19,1, 3.1 GHz i5, 12.7.4, 40 Gb RAM); MacBook Air (1.8 Ghz, 8 Gb RAM, 10.14.6, 256 Gb SSD) Vodafone router and Devolo Wi-Fi Extender, Canon TS8351 printer/scanner.