While was a stable release from February 2017, MikroTik has since released much newer versions (currently v3.40+) that include critical security updates and improved feature support for modern RouterOS versions. Verified Download Steps
Before you deploy Winbox 311 across your network team, run through this checklist: winbox 311 verified download
If you cannot find 3.11 on the official site, the version has likely been retired. In that case, use the — it will still work with legacy routers. While was a stable release from February 2017,