You'll noticeTier: how much it should matter to you
1Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
SandboxArea: what it touches
ImprovementsKind: in v2.1.305,
ImprovementsSection of the release
Unclear It is not clear when Claude Code actually shows this error to a user.
What
The sandbox is the walled-off space Claude Code can run commands in, which limits what those commands can reach. Loopback means network connections a program makes to your own computer, such as a local development server. The network.allowLocalBinding setting asks for that kind of connection to be allowed.
On Windows, the sandbox checks its loopback mode once, when it starts up. Claude Code now has an error message for the case where network.allowLocalBinding asks for a different mode than the one that was checked. The message says:
The Windows loopback mode is fixed by the install.
It cannot change for one command or through updateConfig().
To change it, reset the sandbox and start it up again (reset() then initialize()).
Why
On Windows, the loopback mode cannot be switched on the fly. Changing network.allowLocalBinding partway through will hit an error instead of quietly taking effect.
