diff --git a/Cargo.lock b/Cargo.lock
index 82ddbef..3f3a94b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -285,7 +285,7 @@ checksum = "1d07550c9036bf2ae0c684c4297d503f838287c83c53686d05370d0e139ae570"
 
 [[package]]
 name = "cortiq-gateway"
-version = "0.2.15"
+version = "0.2.16"
 dependencies = [
  "anyhow",
  "arc-swap",
diff --git a/Cargo.toml b/Cargo.toml
index 9f6fde0..1ba04c7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "cortiq-gateway"
-version = "0.2.15"
+version = "0.2.16"
 edition = "2021"
 rust-version = "1.75"
 license = "Apache-2.0"
diff --git a/src/admin/mod.rs b/src/admin/mod.rs
index 955d2fc..d72364c 100644
--- a/src/admin/mod.rs
+++ b/src/admin/mod.rs
@@ -905,12 +905,75 @@ async fn put_settings(State(state): State<SharedState>, Json(b): Json<SettingsBo
         {
             needs_restart = true;
         }
+        let old_servers = cfg.cmf.effective_servers();
         cfg.cmf = v;
+        // Replacing or renaming a managed model must not brick the save: routing
+        // may still reference the old id. Map a vanished id to its replacement
+        // (the new server on the same port), strip ids that are truly gone, and
+        // repair the default so validate() passes.
+        heal_routing_after_cmf_change(&mut cfg, &old_servers);
     }
     state.reload(cfg)?;
     ok(json!({ "ok": true, "needs_restart": needs_restart }))
 }
 
+/// After the managed-servers list changed, rewrite [routing] so it only
+/// references ids that still exist. A removed server whose port is now held by
+/// a NEW server is treated as a replacement (old id → new id); other vanished
+/// ids are stripped. An emptied default falls back to the first managed server,
+/// then the first pool model.
+fn heal_routing_after_cmf_change(cfg: &mut Config, old_servers: &[crate::config::CmfServer]) {
+    let servers = cfg.cmf.effective_servers();
+    let known: std::collections::HashSet<String> = cfg
+        .models
+        .iter()
+        .map(|m| m.id.clone())
+        .chain(servers.iter().map(|s| s.id.clone()))
+        .collect();
+    let new_by_port: HashMap<u16, String> =
+        servers.iter().map(|s| (s.port, s.id.clone())).collect();
+    let mut rename: HashMap<String, String> = HashMap::new();
+    for old in old_servers {
+        if !known.contains(&old.id) {
+            if let Some(new_id) = new_by_port.get(&old.port) {
+                rename.insert(old.id.clone(), new_id.clone());
+            }
+        }
+    }
+    let fix = |id: &str| -> Option<String> {
+        if known.contains(id) {
+            Some(id.to_string())
+        } else {
+            rename.get(id).cloned()
+        }
+    };
+    if !cfg.routing.default.is_empty() {
+        cfg.routing.default = fix(&cfg.routing.default).unwrap_or_default();
+    }
+    if cfg.routing.default.is_empty() {
+        cfg.routing.default = servers
+            .first()
+            .map(|s| s.id.clone())
+            .or_else(|| cfg.models.first().map(|m| m.id.clone()))
+            .unwrap_or_default();
+    }
+    for tt in cfg.routing.tiers.values_mut() {
+        let list = match tt {
+            TierTargets::List(v) => v.clone(),
+            TierTargets::One(s) => vec![s.clone()],
+        };
+        let mut healed: Vec<String> = Vec::new();
+        for id in &list {
+            if let Some(new_id) = fix(id) {
+                if !healed.contains(&new_id) {
+                    healed.push(new_id);
+                }
+            }
+        }
+        *tt = TierTargets::List(healed);
+    }
+}
+
 // ───────────────────────────── cmf runtime ─────────────────────────────────
 /// Status of the `cortiq` CLI (the CMF format runtime): is it installed, which
 /// version, and whether a managed server is running. Drives the "Install cortiq"
@@ -1028,6 +1091,9 @@ async fn cmf_port_check(State(state): State<SharedState>, Query(q): Query<PortQu
     ok(json!({
         "port": port,
         "available": available,
+        // true = held by this gateway's own managed server (a replaced/edited
+        // row frees it on restart) — the UI shows this as info, not an error
+        "managed": running_here,
         "detail": detail,
         "suggested": suggested,
     }))
diff --git a/web/js/i18n/en.js b/web/js/i18n/en.js
index 7858a2f..9ee5825 100644
--- a/web/js/i18n/en.js
+++ b/web/js/i18n/en.js
@@ -267,6 +267,7 @@ export default {
   "settings.cmf.checkPort": "Check port",
   "settings.cmf.portFree": "port is free",
   "settings.cmf.portBusy": "port is in use",
+  "settings.cmf.portOwn": "in use by this gateway's current server — freed on restart, replacing is fine",
   "settings.cmf.useSuggested": "use {port}",
   "settings.cmf.serving": "serving {model} on :{port}",
   "settings.cmf.intro": "Run models locally with the cortiq engine — works even offline or when the router is down.",
diff --git a/web/js/i18n/ru.js b/web/js/i18n/ru.js
index ebb57ce..0ac890c 100644
--- a/web/js/i18n/ru.js
+++ b/web/js/i18n/ru.js
@@ -266,6 +266,7 @@ export default {
   "settings.cmf.checkPort": "Проверить порт",
   "settings.cmf.portFree": "порт свободен",
   "settings.cmf.portBusy": "порт занят",
+  "settings.cmf.portOwn": "занят текущим сервером шлюза — освободится после перезапуска, замена допустима",
   "settings.cmf.useSuggested": "занять {port}",
   "settings.cmf.serving": "работает: {model} на :{port}",
   "settings.cmf.intro": "Запускайте модели локально движком cortiq — работает даже офлайн или когда роутер недоступен.",
diff --git a/web/js/views/settings.js b/web/js/views/settings.js
index 55827aa..dc678a1 100644
--- a/web/js/views/settings.js
+++ b/web/js/views/settings.js
@@ -245,7 +245,11 @@ export async function renderSettings() {
       try {
         const r = await api.cmfPortCheck(p);
         if (r.available) mount(st, h("span", { style: "color:var(--good)" }, "✓ " + t("settings.cmf.portFree")));
-        else {
+        else if (r.managed) {
+          // held by this gateway's own managed server — replacing the model on
+          // this port is fine, it frees up on restart
+          mount(st, h("span", { style: "color:var(--accent)" }, "ℹ " + t("settings.cmf.portOwn")));
+        } else {
           const kids = [h("span", { style: "color:var(--bad)" }, "✗ " + t("settings.cmf.portBusy"))];
           if (r.suggested) { const b = h("button", { class: "btn small", type: "button" }, t("settings.cmf.useSuggested", { port: r.suggested })); b.addEventListener("click", () => { portIn.value = r.suggested; mount(st, ""); }); kids.push(b); }
           mount(st, h("span", {}, ...kids));