Some Users Experiencing System Crashes on macOS 10.15.4, Especially During Large File Transfers
A sizeable number of Mac users are experiencing occasional system crashes after updating to macOS Catalina version 10.15.4, released a few weeks ago.
The crashing issue appears to be most prominent when users attempt to make large file transfers. In a forum post, SoftRAID described the issue as a bug and said that it is working with Apple engineers on a fix for macOS 10.15.5, or a workaround.
SoftRAID said the issue extends to Apple-formatted disks:
There is a serious issue with 10.15.4.
It shows up in different scenarios, even on Apple disks but is more likely when there are lots of IO threads. We think it is a threading issue. So while SoftRAID volumes are hit the hardest (its now hard to copy more than 30GB of data at a time), all systems are impacted by this.
In our bug report to Apple, we used a method to reproduce the problem with ONLY Apple formatted disks. Takes longer to reproduce, but that is more likely to get a faster fix to the user base.
Other users on macOS 10.15.4 have experienced crashes after waking their Mac from sleep, with affected systems suffering a kernel panic and rebooting to the Apple logo, according to comments shared on the Apple Support Communities, MacRumors Forums, Reddit, and Twitter.
After updating to macOS 10.15.4, users may also experience continuous spinning up and spinning down of connected hard drives when a Mac is supposed to be asleep, which could result in damage to the drive, according to Jeremy Horwitz.
We've reached out to Apple for comment and we will provide an update if we hear back.
Popular Stories
Apple is about to release iOS 26.2, the second major point update for iPhones since iOS 26 was rolled out in September, and there are at least 15 notable changes and improvements worth checking out. We've rounded them up below.
Apple is expected to roll out iOS 26.2 to compatible devices sometime between December 8 and December 16. When the update drops, you can check Apple's servers for the ...
Apple is encouraging iPhone users who are still running iOS 18 to upgrade to iOS 26 by making the iOS 26 software upgrade option more prominent.
Since iOS 26 launched in September, it has been displayed as an optional upgrade at the bottom of the Software Update interface in the Settings app. iOS 18 has been the default operating system option, and users running iOS 18 have seen iOS 18...
Apple today seeded the release candidate versions of upcoming iOS 26.2 and iPadOS 26.2 updates to developers and public beta testers, with the software coming two weeks after Apple seeded the third betas. The release candidates represent the final versions of iOS 26.2 and iPadOS 26.2 that will be provided to the public if no further bugs are found during this final week of testing....
In a statement shared with Bloomberg on Wednesday, Apple confirmed that its software design chief Alan Dye will be leaving. Apple said Dye will be succeeded by Stephen Lemay, who has been a software designer at the company since 1999.
Meta CEO Mark Zuckerberg announced that Dye will lead a new creative studio within the company's AR/VR division Reality Labs.
On his blog Daring Fireball,...
We're getting closer to the launch of the final major iOS update of the year, with Apple set to release iOS 26.2 in December. We've had three betas so far and are expecting a fourth beta or a release candidate this week, so a launch could follow as soon as next week.
Past Launch Dates
Apple's past iOS x.2 updates from the last few years have all happened right around the middle of the...
Apple is expected to launch a new foldable iPhone next year, based on multiple rumors and credible sources. The long-awaited device has been rumored for years now, but signs increasingly suggest that 2026 could indeed be the year that Apple releases its first foldable device.
Subscribe to the MacRumors YouTube channel for more videos.
Below, we've collated an updated set of key details that ...
Intel is expected to begin supplying some Mac and iPad chips in a few years, and the latest rumor claims the partnership might extend to the iPhone.
In a research note with investment firm GF Securities this week, obtained by MacRumors, analyst Jeff Pu said he and his colleagues "now expect" Intel to reach a supply deal with Apple for at least some non-pro iPhone chips starting in 2028....
A U.S. appeals court has upheld a temporary restraining order that prevents OpenAI and Jony Ive's new hardware venture from using the name "io" for products similar to those planned by AI audio startup iyO, Bloomberg Law reports.
iyO sued OpenAI earlier this year after the latter announced its partnership with Ive's new firm, arguing that OpenAI's planned "io" branding was too close to its...
The iPhone Air has recorded the steepest early resale value drop of any iPhone model in years, with new data showing that several configurations have lost almost 50% of their value within ten weeks of launch.
According to a ten-week analysis published by SellCell, Apple's latest lineup is showing a pronounced split in resale performance between the iPhone 17 models and the iPhone Air....
iPhone 17 Pro models, it turns out, can't take photos in Night mode when Portrait mode is selected in the Camera app – a capability that's been available on Apple's Pro devices since the iPhone 12 Pro in 2020.
If you're an iPhone 17 Pro or iPhone 17 Pro Max owner, try it for yourself: Open the Camera app with Photo selected in the carousel, then cover the rear lenses with your hand to...
