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
The upcoming iOS 26.1 update includes a handful of new features and changes for iPhones, including a toggle for changing the appearance of the Liquid Glass design, "slide to stop" for alarms in the Clock app, and more.
Below, we outline key details about iOS 26.1.
Release Date
Given that Apple has yet to seed an iOS 26.1 Release Candidate, which is typically the final beta version, the...
Apple is about to drop iOS 26.1, the first major point release since iOS 26 was rolled out in September, and there are at least six notable changes and improvements to look forward to. We've rounded them up below.
Apple has already provided developers and public beta testers with the release candidate version of iOS 26.1, which means Apple will likely roll out the update to all compatible...
Apple is designing an updated version of the Apple TV 4K, and rumors suggest that it could come out sometime in the next couple of months. We're not expecting a major overhaul with design changes, but even a simple chip upgrade will bring major improvements to Apple's set-top box.
Subscribe to the MacRumors YouTube channel for more videos.
We've rounded up all the latest Apple TV rumors.
...
Apple today provided developers and public beta testers with the release candidate versions of upcoming iOS 26.1, iPadOS 26.1, macOS Tahoe 26.1, tvOS 26.1, watchOS 26.1, and visionOS 26.1 updates for testing purposes. The RCs betas come a week after Apple released the fourth betas.
The new betas can be downloaded from the Settings app on a compatible device by going to General > Software...
Apple this month refreshed the 14-inch MacBook Pro base model with its new M5 chip, and higher-end 14-inch and 16-inch MacBook Pro models with M5 Pro and M5 Max chips are expected to follow in early 2026. However, these machines will represent the final update to the current design, with Apple reportedly developing a completely new version of the MacBook Pro packed with next-generation hardware...
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models at the same time, which is why we often get rumored features months ahead of launch. The iPhone 18 series is no different, and we already have a good idea of what to expect for the iPhone 18 Pro and iPhone 18 Pro Max.
One thing worth...
Apple has just given a strong indication that it will not be releasing any additional new Macs for the remainder of the year.
Apple's CFO Kevan Parekh dropped the hint during the company's earnings call on Thursday:On Mac, keep in mind, we expect to face a very difficult compare against the M4 MacBook Pro, Mac mini, and iMac launches in the year-ago quarter.Parekh essentially gave a heads up ...
Apple today provided developers and public beta testers with the release candidate version of macOS Tahoe 26.1, which means the update will likely see a public launch next week.
The release candidate includes notes on what's in the update, so we have a full picture of the new features that Apple has included.
macOS Tahoe 26.1 adds AutoMix support over AirPlay, improved FaceTime audio...
Rumors are stoking excitement for the next-generation iPad mini that Apple is reportedly close to launching. So what should we expect from the successor to the iPad mini 7 that Apple released over a year ago? Read on to find out.
Processor and Performance
Apple is working on a next-generation version of the iPad mini (codename J510/J511) that features the A19 Pro chip, according to...
