{"version":"2.1.305","anchor":"windows-sandbox-profile-read-grants-wfp-loopback-and-reins","canonical_anchor":"windows-sandbox-profile-read-grants-wfp-loopback-and-reins","heading":"Windows sandbox setup checks more and can ask you to reinstall","tier":"notice","area":"Sandbox","scope":"individual","heads_up":true,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.305\/e\/windows-sandbox-profile-read-grants-wfp-loopback-and-reins","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.305","markdown":"### Windows sandbox setup checks more and can ask you to reinstall\n\nOn Windows, sandbox setup now checks profile read access, loopback firewall rules and install state, and can stop with new errors\n\n**Unclear.** It is not clear whether this Windows sandbox setup runs in Claude Code by default.\n\n**What**\n\nThe sandbox is a restricted environment Claude Code can use to run commands with limited access to your files and network. On Windows, setting it up now does much more than before, when it only checked whether the sandbox was installed and checked trusted certificates.\n\nSetup can now stop with these errors:\n\n- `reinstall_required`: the sandbox needs to be installed again\n\n- `wfp_loopback_mismatch`: the firewall rules for local connections on your own machine do not match what is expected\n\n- `profile_grant_outdated`: the recorded permission to read your user profile is out of date\n\n- `profile_exclusion_read_grant`: a permission would reach parts of your profile that are meant to stay unreadable\n\nClaude Code checks a recorded permission that lets sandboxed commands read your user profile folder. If there is none, it logs that your profile is not readable to sandboxed commands in this session. It refuses permissions that would reach profile paths that are excluded from reading, unless the `dangerouslyAllowReadOfProfileExclusions` option is set. The Windows Filtering Platform firewall rules it creates can now allow or block connections to your own machine.\n\n**Why**\n\nIf you use the sandbox on Windows, you may now see new setup errors. Several of them mean you need to run the sandbox install again.\n\n- Area: Sandbox\n- Tier: You'll notice\n- Useful: 3\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: yes"}