Update: the actual error shown in the Software Update control panel is: "Installation failed. An error occurred whiole installing the selected updates"

Here is the log file I found in Console / Log Reports / Installer.log: Notice the errors "The Internet connection appears to be offline" I wonder if it is my USB Ethernet dongle? Or are apple's servers just being hammered? (Sigh - these forums have a very small maximum post limit, so here's a shortened version): 2020-05-23 07:38:45-07 MBA-Catalina softwareupdate_firstrun_tasks[313]: Performing BaseSystem SU Cleanup. 2020-05-23 07:38:45-07 MBA-Catalina storagekitd[315]: Starting SKDaemon... [... many lines deleted ... ] 2020-06-23 08:17:01-07 MBA-Catalina storagekitd[638]: Client entitled for information 2020-06-23 08:17:01-07 MBA-Catalina storagekitd[638]: Adding client connection <NSXPCConnection: 0x7f8712704c40> connection on mach service named com.apple.storagekitd from pid 165 2020-06-23 08:17:03-07 MBA-Catalina syspolicyd[165]: Connected to daemon. Language set to: en 2020-06-23 08:30:42-07 MBA-Catalina softwareupdated[438]: 001-18401-003: Error downloading package InstallAssistant.pkg due to error:(Error Domain=PKDownloadError Code=14 "(null)" UserInfo={NSUnderlyingError=0x7faab1bdcb80 {Error Domain=NSURLErrorDomain Code=-1009 "The Internet connection appears to be offline." UserInfo={_kCFStreamErrorCodeKey=50, NSUnderlyingError=0x7faaaf472d60 {Error Domain=kCFErrorDomainCFNetwork Code=-1009 "(null)" UserInfo={_kCFStreamErrorCodeKey=50, _kCFStreamErrorDomainKey=1}}, _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <9F919B64-B1E9-417A-8F7E-FF360753F2C5>.<1>, _NSURLErrorRelatedURLSessionTaskErrorKey=( 		"LocalDataTask <9F919B64-B1E9-417A-8F7E-FF360753F2C5>.<1>" 2020-06-23 08:30:42-07 MBA-Catalina softwareupdated[438]: 001-18401-003: Downloader has Stopped:<PKDownloader> 			<PKDownloaderQueue> 	 max concurrent downloads: 10 	 0 active downloads: 	 0 queued downloads: 	 total bytes queued: 6122168724 	 bytes completed: 6122168724 	 bytes dequeued so far: 6122168724 	 current progress: 100.000000 	 dequeued progress increment: 0 	 progress derating: inf 	 	 download speed: <PKDownloaderSpeedTracker bps=4980597 with 4402504084 bytes since 2020-06-23 15:15:57 +0000> 	 checksum speed: <PKDownloaderSpeedTracker bps=6939917 with 6113198080 bytes since 2020-06-23 15:15:57 +0000> [... many lines deleted ... ] 2020-06-23 08:30:42-07 MBA-Catalina com.apple.preferences.softwareupdate.remoteservice[430]: SUOSUShimController: Install finished with error: Error Domain=PKDownloadError Code=8 "(null)" UserInfo={NSUnderlyingError=0x600002eb42a0 {Error Domain=NSURLErrorDomain Code=-1009 "The Internet connection appears to be offline." UserInfo={_kCFStreamErrorDomainKey=1, _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <1F14CDD5-B5C1-4C0D-A1C4-0FA3142162F2>.<1>, _NSURLErrorRelatedURLSessionTaskErrorKey=( 		"LocalDataTask <1F14CDD5-B5C1-4C0D-A1C4-0FA3142162F2>.<1>" ), NSLocalizedDescription=The Internet connection appears to be offline., NSErrorFailingURLStringKey=http://swcdn.apple.com/content/downloads/15/52/001-18401-A_I5FFC1VB5J/rrfxkhkf3ykxzj3zjshu1srsh4n74a41n4/InstallAssistant.pkg, NSErrorFailingURLKey=http://swcdn.apple.com/content/downloads/15/52/001-18401-A_I5FFC1VB5J/rrfxkhkf3ykxzj3zjshu1srsh4n74a41n4/InstallAssistant.pkg, _kCFStreamErrorCodeKey=50}}} 2020-06-23 08:30:42-07 MBA-Catalina system_installd[571]: PackageKit: Removing client PKInstallDaemonClient pid=438, uid=200 (/System/Library/CoreServices/Software Update.app/Contents/Resources/softwareupdated) 2020-06-23 09:28:25-07 MBA-Catalina Boot Camp Assistant[853]: Attempting to cancel container resize for disk1 2020-06-23 09:28:25-07 MBA-Catalina Boot Camp Assistant[853]: APFS OS Status: 0x0 2020-06-23 09:28:25-07 MBA-Catalina Boot Camp Assistant[853]: Target disk: disk1 2020-06-23 09:28:25-07 MBA-Catalina Boot Camp Assistant[853]: Could not read disk0s4

Solution: turns out it was the USB Ethernet dongle - I removed that, switched to WiFi, and the download was successful.

This has been submitted as FB8745172

Also seen in the very popular Aerial screen saver https://github.com/JohnCoates/Aerial/issues/1107

More info This only seems to affect Mojave (10.14) The bug seems to crop up depending on the order in which you installed Safari 14 and Security Update 2020-005. If you installed Safari 14 after the security update, then everything is fine. see mrmacintosh.com/mojave-2020-005-security-update-causing-major-problems-updated/

I've seen this on macOS and it seems to be caused by some videos being rendered in hardware. A solution is to use javascript to create a canvas, draw the currebt video frame into the canvas, then show the canvas while you take the screenshot. That seems to force the video content to really get included in the webView properly and then it shows up in the screenshot.

Interesting - if seems that if we set a 0.5 second timer to call StartAnimation from within the Initialize method, it works again. This is probably safe as long as your screensaver can gracefully deal with StartAnimation getting called more than once.

If I can come up with a reproducible case, I will submit a FB report. I think I'm now seeing the problem with Apple screensavers as well. If anyone can try this test, I'd appreciate it: Test 1: Open System Prefernces / Desktop & Screen Saver Select the "Message" screensaver Click Screen Saver Options and enter some text to display "foobar" Result: the apple logo and text are displayed. Test 2: Close System Prefernces Open System Prefernces / Desktop & Screen Saver Result: although the Message screensaver is selected, the Preview is now blank If you click Screen Saver Options and then Cancel, the Preview now shows up Repeating the test with the "Hello" screensaver does not show the bug.

Here's what I see when it's not working, and I can reproduce this issue on 3 different 12.1 systems (M1 and Intel):

Submitted as FB9835060

This bug is still present in 12.2 release version (Silicon and Intel).

I am no longer seeing this issue in the first beta of macOS 13 Ventura (22a5266r)

Still happening in Beta 3 - I've narrowed it down a bit, it appears that any use of WkWebView in a x64 Intel app no longer functions on M1 / ARM macs: Instead, the WebKit process crashes. A standalone ARM build, or a Universal Intel/Arm build work fine. Apple: this is a very bad regression, any insight? I have updated FB11786440 with an XCode sample project to illustrate the crash.

Thanks @eskimo the FB cases we know about are FB12023530 and FB12007471 - the thread which has the most technical details is this one: https://github.com/JohnCoates/Aerial/issues/1286 Note that the bug appears to be random and intermittent, so one successful test doesn't mean it's not happening. Test multiple times.