What exactly did these updates Block?
Per the changelog, computer use on macOS no longer edits or saves hidden files and folders in your home folder (such as ~/.vimrc and ~/.aws) and no longer saves into hidden folders. On October 15 this widened to hidden or protected folders, with Homebrew's folders and shell start-up locations as examples, and to giving a document a hidden or protected name.
Why do this given that there is no Sandbox?
The official guide says computer use has no sandbox between Claude and your applications, and its guardrails are not absolute. With no sandbox, isolation cannot limit the blast radius, so behavioral rules have to fence off locations one by one. This is my inference from reading the two documents together.
What was the keyboard problem in background mode?
The official guide says that on macOS 15 or later Claude works in background windows by default and does not take over your pointer or keyboard. The October 13 update fixed an exception: a dropdown that a click or key opens in a background app is now closed at once instead of swallowing your typing. So it is a patch to background mode, not a new feature.
How should I adjust how I use it?
First confirm the desktop app is v2.42304.0 or later. Do edits to dotfiles, configuration files or shell start-up files yourself. Beyond that, follow the official advice: start with trusted apps, watch Claude's work, stay away from financial accounts and sensitive data, and close anything on screen you do not want seen, since Claude takes screenshots.
Computer use lets Claude look at your screen, click, type and open apps. The official guide is clear that there is no Sandbox between Claude and your applications, and that the trained guardrails "aren't absolute." Against that backdrop, several October updates to the Claude Desktop app simply declare certain write locations off limits.
v2.26454.0 changed computer use on macOS to no longer edit or save hidden files and folders in your home folder, with ~/.vimrc and ~/.aws as the official examples. One is editor configuration; the other typically holds cloud credentials.
v2.31226.0 says computer use no longer saves into hidden folders or types into an app that is not responding. It also fixed menu commands being reported as disabled after an app was briefly busy, screenshots appearing under the wrong step, and text being reported as typed when nothing was.
v2.37337.1 fixed background computer use taking your keyboard: a dropdown that a click or key opens in a background app is now closed at once instead of swallowing what you type.
v2.42304.0 widened the scope: no saving files into hidden or protected folders, with Homebrew's folders and shell start-up locations as the official examples, and no giving a document a hidden or protected name. The same release fixed text being typed twice into a busy web page.
The changelog describes behavior and gives no motive. A reasonable inference is that home-folder dotfiles, cloud credential folders and shell start-up files are places where one wrong write has large consequences and is hard to notice, so they were fenced off first. That is my inference, not an official statement.
If your workflow ever asked Claude to adjust dotfiles, configuration files or shell start-up files on a Mac, such writes will be refused after October, so you do them yourself or use a route that does not depend on computer use. Conversely, these protections cover only the locations the changelog lists. The guide still advises against using computer use for financial accounts, legal documents and medical information, and recommends watching Claude's work early on. Computer use is currently in beta on Pro and Max; Team and Enterprise do not have it.