Several users reported that they are facing issues when they update to the new macOS 10.15.4. These users report occasional system crashes especially when they try to transfer large files.
Apple updated the macOS with its new Catalina 10.15.4 a couple of weeks before. SoftRAID described in an online forum post that the issue is a bug. Apple is working on it and will fix the issue with the later release.
The users do not only face the issue while transferring files but also many other times. The issue is also with the disks. The bug crashes the system on various scenarios. It crashes on Apple disks. It also crashes when there are too many IO threads.
Several users are reporting this issue on Twitter.
SoftRAID also told that they shared the bug reports with Apple. The bug report also mentions that SoftRAID reproduced the issue using a method only for Apple formatted disks. The report mentions that it does take long to reproduce the problem.