Browser control crashes during initialization — Windows

What version of the Codex App are you using (From “About Codex” dialog)?

26.903.61454

What subscription do you have?

Pro

What platform is your computer?

Windows 11

What issue are you seeing?

Since September 5, Codex has been unable to control the built-in browser. I can open YouTube myself, but the agent crashes at cua.getState() and cua.getBrowser(...).
Recurring error messages:
windows sandbox failed: helper_unknown_error: setup refresh had errors
trusted Node process exited unexpectedly; kernel reset, rerun your request
Retrying and resetting the browser session do not help. Standard shell commands within the sandbox also fail; the same commands work outside the sandbox.
Expected: the agent can view and control the open tab.
Actual: the helper process stops before the tab is read.

What steps can reproduce the bug?

open a youtube video, let codex try to view the video

What is the expected behavior?

the agent can view and control the open tab.

Additional information

No response

Reproduce on Windows 11 by opening a YouTube video and observing failures at cua.getState() and cua.getBrowser(...). Start with the Windows sandbox errors and trusted Node process reset, then compare the failing sandbox shell commands with the same commands outside it. Done means the helper remains running and the agent can view and control the open tab.