macOS 10.15.6

Apple (also: MacRumors, Mr. Macintosh, Howard Oakley):

macOS Catalina 10.15.6 introduces local news in your Today feed in Apple News and improves the security and reliability of your Mac.

Unlike macOS 10.15.5, this does include a new version of Apple Mail. However, it’s not yet clear to me whether it fixes the data loss bug from macOS 10.15.0 where messages disappear when you move them. One user who had been frequently seeing the problem says that it stopped occurring some time ago—after the previous update but before this one—perhaps due to a change on Apple’s iCloud mail server. However, I would still like to see a fix in Mail itself because the bug also affected Gmail and other servers.

I have heard that some users are still seeing the bug from 10.15.0 where rules don’t move incoming messages to another mailbox automatically, only when manually applying the rules.

Update (2020-07-16): I received another report that iCloud messages no longer disappear. I also received a report that the bug with rules copying Gmail messages instead of moving them is fixed. I’m still not sure whether the data loss bug is fixed for non-iCloud servers.

Update (2020-07-20): One user reports Exchange messages disappearing when moved, although he’s not sure whether it’s due to a server problem or Apple Mail.

Update (2020-08-03): I’ve received several other reports of messages disappearing when moving them.

Previously:

• macOS 10.15.5
• Mail Data Loss in macOS 10.15
• Waiting to Update to Catalina

Update (2020-07-27): Mr. Macintosh:

The softwareupdate --ignore flag was changed to include some changes that we asked for!

Erik Schwiebert:

PSA: beware of MacOS [10.15.5] if you have any non-ASCII characters in your apps’ entitlement.plist files (even if they are HTML-encoded with &#...;). Late changes to the codesign tool error on them at signing time.

Juli Clover:

macOS Catalina 10.15.6 successfully fixes a frustrating bug that prevented some USB 2.0 accessories from working properly with 2020 MacBook Air and MacBook Pro models, according to MacRumors readers and users on Reddit.

Ole Begemann:

macOS 10.15.6 understands Big Sur’s APFS volume format. And apparently parallel installs of Catalina and Big Sur into the same APFS container are now supported (though I haven’t tried this).

Previously:

• Installing the macOS 11.0 Beta

Update (2020-07-29): Tanner Bennett:

You can only use the --ignore flag “as long as the Mac is enrolled in Apple School Manager, Apple Business Manager or a User Approved MDM”?

Why?

Update (2020-08-07): Howard Oakley:

My iMac Pro had clearly suffered a kernel panic as a result of a memory leak, which ran zone kalloc.48 out of memory, which it couldn’t recover. This may be unassociated with the bug that’s affecting virtualisation software, but makes me suspect that they result from the same memory leak. In which case, any Mac running 10.15.6 could be so affected.

I hope that Apple’s engineers are onto this case, and that we’ll soon see a Supplemental Update to 10.15.6.

Leo:

My MBP kps and shuts down every three days. When I boot back up iStat menus shows the last temp reading before (thermal?) shutdown, 100 deg C, before reading sensor data.