What each core is for

  • Xray: best support for VMess / VLESS / REALITY, the everyday default.
  • sing-box: needed for newer protocols like Hysteria2, TUIC and WireGuard.

How to switch

In Parameter settings → Core type, you can assign a core per protocol, or set it per node via right-click. If a switch reports a missing core, update that core first.

Recommendation

Without a special protocol need, keep the default Xray; when a hysteria2:// or tuic:// link won't connect, switch just that node to sing-box.