diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6a36ad4..e4403dc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,11 @@ CalVer image tags (`stable-YYYY.MM.N`, `dev-YYYY.MM.N`) are produced for every C
 
 ## [Unreleased]
 
+## [0.51.1] — 2026-05-12
+
+### Fixed
+- **`/corporate-memory/admin` no longer fails with "Error loading pending items." once pending knowledge items exist.** `GET /corporate-memory/admin` was passing the `corporate_memory.groups` YAML section (a dict, default `{}`) into the template as `groups=`, but `renderItemCard` evaluates `GROUPS.map(g => ...)` to build the mandate-form audience picker — `{}.map is not a function` threw inside the template literal, bubbled up to `renderReviewItems`, and the `loadReviewQueue` catch block painted the misleading "Error loading pending items." banner over a perfectly valid `/api/memory/admin/pending` response. Bug was dormant since the initial system commit because `renderItemCard` only runs when at least one pending item exists, so test fixtures and empty queues never tripped it. Fix: route now passes RBAC user_groups (`user_groups` table) shaped as `[{name, members_count}]`, which is what the mandate form actually targets (audience targeting is `group:<rbac-group-name>`, not `corporate_memory.groups`); template hardens the `.map` call with `Array.isArray(GROUPS) ? GROUPS : []` so a future shape regression degrades to "no group options" instead of crashing the whole list. No DB migration; no API change.
+
 ## [0.51.0] — 2026-05-12
 
 ### Fixed
diff --git a/app/web/router.py b/app/web/router.py
index 42479e2..386656f 100644
--- a/app/web/router.py
+++ b/app/web/router.py
@@ -974,6 +974,21 @@ async def corporate_memory_admin(
         "WHERE relation_type = 'likely_duplicate' AND resolved = FALSE"
     ).fetchone()[0]
 
+    # Mandate-form audience picker needs RBAC user_groups, not the
+    # `corporate_memory.groups` YAML section — those are unrelated.
+    # Template expects an array of {name, members_count} so it can render
+    # `<option value="group:<name>">` rows in the per-item mandate form;
+    # the previous shape (`{}` from the YAML config) crashed renderItemCard
+    # with "GROUPS.map is not a function" the moment any pending item rendered.
+    from src.repositories.user_groups import UserGroupsRepository as _UserGroupsRepo
+    from src.repositories.user_group_members import UserGroupMembersRepository as _UserGroupMembersRepo
+    _groups_repo = _UserGroupsRepo(conn)
+    _members_repo = _UserGroupMembersRepo(conn)
+    user_groups_for_ui = [
+        {"name": g["name"], "members_count": _members_repo.count_members(g["id"])}
+        for g in _groups_repo.list_all()
+    ]
+
     ctx = _build_context(
         request, user=user,
         pending_items=pending,
@@ -989,7 +1004,7 @@ async def corporate_memory_admin(
             "duplicates": duplicates_count,
         },
         governance=get_corporate_memory_config(),
-        groups=get_corporate_memory_config().get("groups", {}),
+        groups=user_groups_for_ui,
         contradictions=contradictions,
         audit_entries=[],
     )
diff --git a/app/web/templates/corporate_memory_admin.html b/app/web/templates/corporate_memory_admin.html
index 84e90e8..da60703 100644
--- a/app/web/templates/corporate_memory_admin.html
+++ b/app/web/templates/corporate_memory_admin.html
@@ -1738,7 +1738,7 @@
                 <label style="margin-top: var(--space-3);">Target Audience</label>
                 <select id="mandate-audience-${esc(item.id)}">
                     <option value="all">All users</option>
-                    ${GROUPS.map(g => `<option value="group:${esc(g.name)}">${esc(g.name)} (${g.members_count} members)</option>`).join('')}
+                    ${(Array.isArray(GROUPS) ? GROUPS : []).map(g => `<option value="group:${esc(g.name)}">${esc(g.name)} (${g.members_count} members)</option>`).join('')}
                 </select>
                 <div class="mandate-form-actions">
                     <button class="btn btn-mandate" onclick="submitMandate('${esc(item.id)}')">Confirm</button>
diff --git a/pyproject.toml b/pyproject.toml
index f8f5b43..1794693 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "agnes-the-ai-analyst"
-version = "0.51.0"
+version = "0.51.1"
 description = "Agnes — AI Data Analyst platform for AI analytical systems"
 requires-python = ">=3.11,<3.14"
 license = "MIT"
diff --git a/tests/test_corporate_memory_page.py b/tests/test_corporate_memory_page.py
index 6fb5faa..f608024 100644
--- a/tests/test_corporate_memory_page.py
+++ b/tests/test_corporate_memory_page.py
@@ -70,3 +70,28 @@ class TestNonAdminBlocked:
         token = seeded_app["analyst_token"]
         resp = c.get("/corporate-memory", headers=_auth(token))
         assert resp.status_code == 403
+
+
+class TestAdminGroupsContract:
+    def test_admin_page_renders_groups_as_array_not_dict(self, seeded_app):
+        """`/corporate-memory/admin` must serialize `groups` as a JS array
+        of `{name, members_count}` rows. Earlier the route passed the
+        `corporate_memory.groups` YAML config (a dict, default `{}`),
+        so `GROUPS.map(...)` inside `renderItemCard` threw
+        `{}.map is not a function` and the page surfaced a misleading
+        "Error loading pending items" banner over a perfectly valid
+        pending payload. Bug was dormant because `renderItemCard` only
+        runs when ≥1 pending item exists. This test seeds one pending
+        item and asserts the array shape so the regression can't return."""
+        _seed_pending_item("groups_shape_1")
+        c = seeded_app["client"]
+        token = seeded_app["admin_token"]
+        resp = c.get("/corporate-memory/admin", headers=_auth(token))
+        assert resp.status_code == 200
+        body = resp.text
+        # JS literal must be an array — even when empty it is `[]`, never `{}`.
+        assert "const GROUPS = [" in body, (
+            "groups must serialize as a JS array of {name, members_count}; "
+            "a `{` prefix means we regressed to passing a dict and "
+            "renderItemCard's GROUPS.map(...) will crash at runtime."
+        )