https://wccftech.com/some-users-are-facing-random-system-crashes-on-macos-10-15-4/

A large number of macOS Catalina 10.15.4 users are experiencing occasional system crashes. The update was released a week ago and users are complaining of random crashes, especially during the transferring of large files.

As mentioned earlier, the system crashes mostly happen when users attempt to transfer large files. According to the forum post, SoftRAID states that the issue is because if a bug and that it is working with Apple engineers to bring a fix for macOS 10.15.5.