diff --git a/crates/api/src/admin_vocab.rs b/crates/api/src/admin_vocab.rs
index e42d446..18a2e71 100644
--- a/crates/api/src/admin_vocab.rs
+++ b/crates/api/src/admin_vocab.rs
@@ -185,9 +185,15 @@ pub(crate) async fn add_term(
         .await
         .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
 
-    let term_id = db::vocab::add_term(&mut tx, &new)
-        .await
-        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+    let term_id = db::vocab::add_term(&mut tx, &new).await.map_err(|err| {
+        // A well-formed id for a missing vocabulary hits the FK constraint (23503).
+        if err.as_database_error().and_then(|e| e.code()).as_deref() == Some("23503") {
+            StatusCode::NOT_FOUND
+        } else {
+            tracing::error!(?err, "adding term");
+            StatusCode::INTERNAL_SERVER_ERROR
+        }
+    })?;
 
     tx.commit()
         .await
diff --git a/crates/api/src/public.rs b/crates/api/src/public.rs
index b36f2c7..15a5d05 100644
--- a/crates/api/src/public.rs
+++ b/crates/api/src/public.rs
@@ -71,11 +71,17 @@ pub(crate) async fn list_objects(
     // public read surface.
     let objects = db::catalog::list_public_objects(state.db.pool(), limit, offset)
         .await
-        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+        .map_err(|err| {
+            tracing::error!(?err, "listing public objects");
+            StatusCode::INTERNAL_SERVER_ERROR
+        })?;
 
     let total = db::catalog::count_public_objects(state.db.pool())
         .await
-        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+        .map_err(|err| {
+            tracing::error!(?err, "counting public objects");
+            StatusCode::INTERNAL_SERVER_ERROR
+        })?;
 
     Ok(Json(PublicObjectPage {
         items: objects.iter().map(PublicView::from_object).collect(),
@@ -106,7 +112,10 @@ pub(crate) async fn get_object(
     match db::catalog::public_object_by_id(state.db.pool(), object_id).await {
         Ok(Some(object)) => Json(PublicView::from_object(&object)).into_response(),
         Ok(None) => StatusCode::NOT_FOUND.into_response(),
-        Err(_) => StatusCode::INTERNAL_SERVER_ERROR.into_response(),
+        Err(err) => {
+            tracing::error!(?err, "fetching public object");
+            StatusCode::INTERNAL_SERVER_ERROR.into_response()
+        }
     }
 }
 
diff --git a/crates/api/tests/admin_catalog.rs b/crates/api/tests/admin_catalog.rs
index 9ef9e8a..d9e4594 100644
--- a/crates/api/tests/admin_catalog.rs
+++ b/crates/api/tests/admin_catalog.rs
@@ -263,3 +263,30 @@ async fn create_and_list_authorities_by_kind(pool: PgPool) {
     let bad = app2_get(&app, &cookie, "/api/admin/authorities?kind=alien").await;
     assert_eq!(bad, StatusCode::UNPROCESSABLE_ENTITY);
 }
+
+#[sqlx::test(migrations = "../db/migrations")]
+async fn add_term_to_missing_vocabulary_is_404(pool: PgPool) {
+    migrate_sessions(&db::Db::from_pool(pool.clone()))
+        .await
+        .unwrap();
+
+    seed_user(&pool, "ed@example.com", "pw-editor-123", Role::Editor).await;
+
+    let app = build_app(state(pool));
+    let cookie = login(&app, "ed@example.com", "pw-editor-123").await;
+
+    let resp = app
+        .oneshot(
+            Request::builder()
+                .method("POST")
+                .uri("/api/admin/vocabularies/00000000-0000-0000-0000-000000000000/terms")
+                .header(header::COOKIE, &cookie)
+                .header(header::CONTENT_TYPE, "application/json")
+                .body(Body::from(r#"{"labels":[{"lang":"en","label":"X"}]}"#))
+                .unwrap(),
+        )
+        .await
+        .unwrap();
+
+    assert_eq!(resp.status(), StatusCode::NOT_FOUND);
+}
diff --git a/crates/domain/src/audit.rs b/crates/domain/src/audit.rs
index f9d7114..238dd3c 100644
--- a/crates/domain/src/audit.rs
+++ b/crates/domain/src/audit.rs
@@ -4,6 +4,10 @@ use time::OffsetDateTime;
 use uuid::Uuid;
 
 /// What kind of change an audit entry records.
+///
+/// NOTE: kept in sync by hand with the
+/// `CHECK (action IN ('created', 'updated', 'deleted'))` constraint in
+/// `crates/db/migrations/0001_audit_log.sql` — add a variant in both places.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "lowercase")]
 pub enum AuditAction {
diff --git a/crates/domain/src/authority.rs b/crates/domain/src/authority.rs
index 299b1a1..7cc550e 100644
--- a/crates/domain/src/authority.rs
+++ b/crates/domain/src/authority.rs
@@ -3,6 +3,10 @@ use serde::{Deserialize, Serialize};
 use crate::{AuthorityId, LocalizedLabel};
 
 /// The kind of authority record.
+///
+/// NOTE: kept in sync by hand with the
+/// `CHECK (kind IN ('person', 'organisation', 'place'))` constraint in
+/// `crates/db/migrations/0002_vocabularies_authorities.sql` — add a variant in both places.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "lowercase")]
 pub enum AuthorityKind {
diff --git a/crates/server/src/lib.rs b/crates/server/src/lib.rs
index ae630b8..a355cd6 100644
--- a/crates/server/src/lib.rs
+++ b/crates/server/src/lib.rs
@@ -50,7 +50,7 @@ pub async fn run(config: Config) -> anyhow::Result<()> {
 
     let state = AppState {
         db,
-        app_name: config.app_name.clone(),
+        app_name: config.app_name,
         cookie_secure: config.cookie_secure,
         search,
     };
diff --git a/crates/server/tests/serve.rs b/crates/server/tests/serve.rs
index aa15497..b3dd99d 100644
--- a/crates/server/tests/serve.rs
+++ b/crates/server/tests/serve.rs
@@ -22,13 +22,21 @@ async fn serves_health_live_over_tcp() {
     let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
     let addr: SocketAddr = listener.local_addr().unwrap();
 
-    let handle = tokio::spawn(async move {
-        serve(listener, state).await.unwrap();
-    });
+    let handle = tokio::spawn(async move { serve(listener, state).await });
 
     let url = format!("http://{addr}/health/live");
-    let body: serde_json::Value = reqwest::get(&url)
-        .await
+    let response = reqwest::get(&url).await;
+
+    // If the request failed and the server task already ended, it errored — surface that
+    // (a clear server error) instead of the opaque reqwest failure.
+    if response.is_err() && handle.is_finished() {
+        match handle.await {
+            Ok(Err(err)) => panic!("server failed: {err:?}"),
+            other => panic!("server task ended unexpectedly: {other:?}"),
+        }
+    }
+
+    let body: serde_json::Value = response
         .expect("request succeeds")
         .json()
         .await
diff --git a/web/src/api/queries.ts b/web/src/api/queries.ts
index 0825ec9..d53d672 100644
--- a/web/src/api/queries.ts
+++ b/web/src/api/queries.ts
@@ -3,6 +3,13 @@ import { keepPreviousData, useInfiniteQuery, useMutation, useQuery, useQueryClie
 import { api } from "./client";
 import type { components } from "./schema";
 
+export class HttpError extends Error {
+  constructor(public readonly status: number) {
+    super(`HTTP ${status}`);
+    this.name = "HttpError";
+  }
+}
+
 type UserView = components["schemas"]["UserView"];
 type LoginRequest = components["schemas"]["LoginRequest"];
 
@@ -291,7 +298,7 @@ export function useSearch(q: string, visibility: string | null) {
     enabled: term.length > 0,
     initialPageParam: 0,
     queryFn: async ({ pageParam }) => {
-      const { data, error } = await api.GET("/api/admin/search", {
+      const { data, error, response } = await api.GET("/api/admin/search", {
         params: {
           query: {
             q: term,
@@ -302,7 +309,7 @@ export function useSearch(q: string, visibility: string | null) {
         },
       });
 
-      if (error || !data) throw new Error("search failed");
+      if (error || !data) throw new HttpError(response.status);
 
       return data;
     },
diff --git a/web/src/authorities/authorities-page.tsx b/web/src/authorities/authorities-page.tsx
index 06d03f2..13aa20d 100644
--- a/web/src/authorities/authorities-page.tsx
+++ b/web/src/authorities/authorities-page.tsx
@@ -18,8 +18,9 @@ export function AuthoritiesPage() {
   const lang = i18n.language.startsWith("sv") ? "sv" : "en";
 
   const isValidKind = (KINDS as readonly string[]).includes(kind ?? "");
+  const currentKind = isValidKind ? (kind as string) : "person";
 
-  const { data: authorities } = useAuthorities(isValidKind ? (kind as string) : "person");
+  const { data: authorities, isLoading, isError } = useAuthorities(currentKind);
   const create = useCreateAuthority();
 
   const [labels, setLabels] = useState<LabelInput[]>([]);
@@ -44,11 +45,13 @@ export function AuthoritiesPage() {
 
   return (
     <div className="overflow-auto p-4">
-      <div className="mb-3 flex gap-2">
+      <div role="tablist" className="mb-3 flex gap-2">
         {KINDS.map((k) => (
           <NavLink
             key={k}
             to={`/authorities/${k}`}
+            role="tab"
+            aria-selected={k === currentKind}
             className={({ isActive }) =>
               `rounded px-3 py-1 text-sm ${isActive ? "bg-neutral-800 text-white" : "border"}`
             }
@@ -59,7 +62,13 @@ export function AuthoritiesPage() {
       </div>
 
       <ul className="mb-4">
-        {authorities?.length === 0 && (
+        {isLoading && (
+          <li className="text-sm text-neutral-400">…</li>
+        )}
+        {isError && (
+          <li className="text-sm text-red-600">{t("authorities.loadError")}</li>
+        )}
+        {!isLoading && !isError && authorities?.length === 0 && (
           <li className="text-sm text-neutral-500">{t("authorities.empty")}</li>
         )}
         {authorities?.map((a) => (
@@ -71,7 +80,7 @@ export function AuthoritiesPage() {
 
       <form onSubmit={onCreate} className="space-y-2 border-t pt-3">
         <div className="text-sm font-medium">
-          {t("authorities.new")} · {t(`authorities.${kind}`)}
+          {t("authorities.new")} · {t(`authorities.${currentKind}`)}
         </div>
 
         <LabelEditor value={labels} onChange={setLabels} />
diff --git a/web/src/authorities/authorities.test.tsx b/web/src/authorities/authorities.test.tsx
index 58e49c3..67406a7 100644
--- a/web/src/authorities/authorities.test.tsx
+++ b/web/src/authorities/authorities.test.tsx
@@ -33,7 +33,13 @@ test("lists authorities for the kind and creates one", async () => {
 
 test("kind tabs link to the other kinds", async () => {
   renderApp(tree(), { route: "/authorities/person" });
-  expect(await screen.findByRole("link", { name: /place/i })).toHaveAttribute("href", "/authorities/place");
+  expect(await screen.findByRole("tab", { name: /place/i })).toHaveAttribute("href", "/authorities/place");
+});
+
+test("aria-selected is on the tab element and reflects the active kind", async () => {
+  renderApp(tree(), { route: "/authorities/person" });
+  expect(await screen.findByRole("tab", { name: /^person$/i })).toHaveAttribute("aria-selected", "true");
+  expect(screen.getByRole("tab", { name: /^place$/i })).toHaveAttribute("aria-selected", "false");
 });
 
 test("create without EN label shows required alert and does not POST", async () => {
@@ -51,6 +57,14 @@ test("create without EN label shows required alert and does not POST", async ()
   expect(posted).toBe(false);
 });
 
+test("authorities endpoint error shows loadError", async () => {
+  server.use(
+    http.get("/api/admin/authorities", () => new HttpResponse(null, { status: 500 })),
+  );
+  renderApp(tree(), { route: "/authorities/person" });
+  expect(await screen.findByText(/could not load/i)).toBeInTheDocument();
+});
+
 test("unknown kind redirects to person list", async () => {
   renderApp(tree(), { route: "/authorities/banana" });
   expect(await screen.findByText("Ada Lovelace")).toBeInTheDocument();
diff --git a/web/src/fields/fields.test.tsx b/web/src/fields/fields.test.tsx
index 87fdceb..a3df0e8 100644
--- a/web/src/fields/fields.test.tsx
+++ b/web/src/fields/fields.test.tsx
@@ -43,6 +43,27 @@ test("creates a text field — posts the body and clears the key input", async (
   await waitFor(() => expect(screen.getByLabelText(/^key$/i)).toHaveValue(""));
 });
 
+test("selecting Authority reveals the kind picker and posts the chosen kind", async () => {
+  let body: { authority_kind: string | null } | undefined;
+
+  server.use(
+    http.post("/api/admin/field-definitions", async ({ request }) => {
+      body = (await request.json()) as { authority_kind: string | null };
+      return HttpResponse.json({ key: "maker" }, { status: 201 });
+    }),
+  );
+  renderApp(tree(), { route: "/fields" });
+
+  await userEvent.type(screen.getByLabelText(/^key$/i), "maker");
+  await userEvent.type(screen.getByLabelText(/label \(en\)/i), "Maker");
+  await userEvent.selectOptions(screen.getByLabelText(/^type$/i), "authority");
+  const kind = await screen.findByLabelText(/authority kind/i);
+  await userEvent.selectOptions(kind, "person");
+  await userEvent.click(screen.getByRole("button", { name: /create field/i }));
+
+  await waitFor(() => expect(body?.authority_kind).toBe("person"));
+});
+
 test("selecting Term reveals the vocabulary picker and blocks submit until chosen", async () => {
   let posted = false;
 
diff --git a/web/src/i18n/en.json b/web/src/i18n/en.json
index 9c27be1..0e61bc9 100644
--- a/web/src/i18n/en.json
+++ b/web/src/i18n/en.json
@@ -9,13 +9,13 @@
   "actions": { "edit": "Edit", "delete": "Delete", "confirmDelete": "Delete this object? This cannot be undone." },
   "labels": { "en": "Label (EN)", "sv": "Label (SV)", "externalUri": "External URI (optional)" },
   "vocab": {
-    "title": "Vocabularies", "newVocabulary": "New vocabulary", "key": "Key",
+    "newVocabulary": "New vocabulary", "key": "Key",
     "create": "Create", "selectPrompt": "Select a vocabulary to manage its terms",
     "terms": "Terms", "addTerm": "Add term", "empty": "No vocabularies yet",
     "noTerms": "No terms yet", "loadError": "Could not load"
   },
   "authorities": {
-    "title": "Authorities", "person": "Person", "organisation": "Organisation", "place": "Place",
+    "person": "Person", "organisation": "Organisation", "place": "Place",
     "new": "New", "create": "Create", "empty": "No authorities yet", "loadError": "Could not load"
   },
   "search": {
@@ -24,6 +24,7 @@
     "prompt": "Type to search",
     "empty": "No results",
     "loadError": "Search is unavailable",
+    "unavailable": "Search is not available on this server",
     "loadMore": "Load more",
     "resultCount_one": "{{count}} result",
     "resultCount_other": "{{count}} results",
diff --git a/web/src/i18n/sv.json b/web/src/i18n/sv.json
index 833b5ff..844a80a 100644
--- a/web/src/i18n/sv.json
+++ b/web/src/i18n/sv.json
@@ -9,13 +9,13 @@
   "actions": { "edit": "Redigera", "delete": "Ta bort", "confirmDelete": "Ta bort detta föremål? Detta kan inte ångras." },
   "labels": { "en": "Etikett (EN)", "sv": "Etikett (SV)", "externalUri": "Extern URI (valfritt)" },
   "vocab": {
-    "title": "Vokabulär", "newVocabulary": "Ny vokabulär", "key": "Nyckel",
+    "newVocabulary": "Ny vokabulär", "key": "Nyckel",
     "create": "Skapa", "selectPrompt": "Välj en vokabulär för att hantera dess termer",
     "terms": "Termer", "addTerm": "Lägg till term", "empty": "Inga vokabulärer ännu",
     "noTerms": "Inga termer ännu", "loadError": "Kunde inte ladda"
   },
   "authorities": {
-    "title": "Auktoriteter", "person": "Person", "organisation": "Organisation", "place": "Plats",
+    "person": "Person", "organisation": "Organisation", "place": "Plats",
     "new": "Ny", "create": "Skapa", "empty": "Inga auktoriteter ännu", "loadError": "Kunde inte ladda"
   },
   "search": {
@@ -24,6 +24,7 @@
     "prompt": "Skriv för att söka",
     "empty": "Inga träffar",
     "loadError": "Sök är inte tillgängligt",
+    "unavailable": "Sök är inte tillgängligt på den här servern",
     "loadMore": "Visa fler",
     "resultCount_one": "{{count}} träff",
     "resultCount_other": "{{count}} träffar",
diff --git a/web/src/search/search-panel.tsx b/web/src/search/search-panel.tsx
index 701e9b5..3cf9de9 100644
--- a/web/src/search/search-panel.tsx
+++ b/web/src/search/search-panel.tsx
@@ -2,7 +2,7 @@ import { useEffect, useState } from "react";
 import { useSearchParams } from "react-router-dom";
 import { useTranslation } from "react-i18next";
 
-import { useSearch } from "../api/queries";
+import { useSearch, HttpError } from "../api/queries";
 import { useDebouncedValue } from "../lib/use-debounced-value";
 import { SearchResultRow } from "./search-result-row";
 import { Button } from "@/components/ui/button";
@@ -92,7 +92,11 @@ export function SearchPanel() {
         )}
 
         {hasQuery && search.isError && (
-          <p className="p-4 text-sm text-red-600">{t("search.loadError")}</p>
+          <p className="p-4 text-sm text-red-600">
+            {search.error instanceof HttpError && search.error.status === 503
+              ? t("search.unavailable")
+              : t("search.loadError")}
+          </p>
         )}
 
         {hasQuery && !search.isLoading && !search.isError && hits.length === 0 && (
diff --git a/web/src/search/search.test.tsx b/web/src/search/search.test.tsx
index 0edfb79..66ba609 100644
--- a/web/src/search/search.test.tsx
+++ b/web/src/search/search.test.tsx
@@ -76,6 +76,20 @@ test("clicking a result shows the object in the detail pane", async () => {
   expect(await screen.findByText(amphora.object_name)).toBeInTheDocument();
 });
 
+test("a 503 shows the search-unavailable message", async () => {
+  server.use(http.get("/api/admin/search", () => new HttpResponse(null, { status: 503 })));
+  renderApp(tree(), { route: "/search" });
+  await userEvent.type(screen.getByLabelText(/search the collection/i), "bronze");
+  expect(await screen.findByText(/not available on this server/i)).toBeInTheDocument();
+});
+
+test("a 500 shows the generic search error", async () => {
+  server.use(http.get("/api/admin/search", () => new HttpResponse(null, { status: 500 })));
+  renderApp(tree(), { route: "/search" });
+  await userEvent.type(screen.getByLabelText(/search the collection/i), "bronze");
+  expect(await screen.findByText(/^search is unavailable$/i)).toBeInTheDocument();
+});
+
 test("hydrates query and visibility from the initial URL", async () => {
   renderApp(tree(), { route: "/search?q=bronze" });
 
diff --git a/web/src/vocab/vocabularies.test.tsx b/web/src/vocab/vocabularies.test.tsx
index 9e7b30a..38e731c 100644
--- a/web/src/vocab/vocabularies.test.tsx
+++ b/web/src/vocab/vocabularies.test.tsx
@@ -52,6 +52,14 @@ test("selecting a vocabulary shows its terms and adds one", async () => {
   );
 });
 
+test("terms endpoint error shows vocab loadError", async () => {
+  server.use(
+    http.get("/api/admin/vocabularies/:id/terms", () => new HttpResponse(null, { status: 500 })),
+  );
+  renderApp(tree(), { route: "/vocabularies/v-material" });
+  expect(await screen.findByText(/could not load/i)).toBeInTheDocument();
+});
+
 test("add term without EN label shows required alert and does not POST", async () => {
   let posted = false;
   server.use(
diff --git a/web/src/vocab/vocabulary-terms.tsx b/web/src/vocab/vocabulary-terms.tsx
index f6cb86f..1d8d886 100644
--- a/web/src/vocab/vocabulary-terms.tsx
+++ b/web/src/vocab/vocabulary-terms.tsx
@@ -19,7 +19,7 @@ export function VocabularyTerms() {
 
   const lang = i18n.language.startsWith("sv") ? "sv" : "en";
 
-  const { data: terms } = useTerms(id);
+  const { data: terms, isLoading, isError } = useTerms(id);
 
   const addTerm = useAddTerm();
 
@@ -53,7 +53,13 @@ export function VocabularyTerms() {
         {t("vocab.terms")}
       </h3>
       <ul className="mb-4">
-        {terms?.length === 0 && (
+        {isLoading && (
+          <li className="text-sm text-neutral-400">…</li>
+        )}
+        {isError && (
+          <li className="text-sm text-red-600">{t("vocab.loadError")}</li>
+        )}
+        {!isLoading && !isError && terms?.length === 0 && (
           <li className="text-sm text-neutral-500">{t("vocab.noTerms")}</li>
         )}
         {terms?.map((term) => (