diff --git a/backend/migrations/0003_open_tasks_by_assignee_preset_accounts.sql b/backend/migrations/0003_open_tasks_by_assignee_preset_accounts.sql
new file mode 100644
index 0000000..7517f36
--- /dev/null
+++ b/backend/migrations/0003_open_tasks_by_assignee_preset_accounts.sql
@@ -0,0 +1,25 @@
+-- 0003_open_tasks_by_assignee_preset_accounts.sql
+-- Core migration 000066 moved a person's or agent's display name off `users`
+-- and `agents` onto `accounts`, and replaced project_members.user_id/agent_id
+-- with project_members.account_id. The "Open tasks by assignee" preset read
+-- the old columns, so every panel created from it would now fail.
+--
+-- Panels copy the preset's SQL when they are created, so rewrite the ones that
+-- still hold the preset text unchanged (compared ignoring whitespace). A panel
+-- the user has edited is left alone: it is theirs to adapt, and the plugin
+-- shows the query error when it fails.
+-- Run with search_path = plugin_data_com_paca_dashboard, public.
+
+UPDATE dashboard_panels
+SET query = $new$SELECT COALESCE(ac.name, 'Unassigned') AS assignee, COUNT(DISTINCT t.id) AS open_tasks
+FROM tasks t
+JOIN task_statuses ts ON ts.id = t.status_id
+LEFT JOIN task_assignees ta ON ta.task_id = t.id
+LEFT JOIN project_members pm ON pm.id = ta.member_id
+LEFT JOIN accounts ac ON ac.id = pm.account_id
+WHERE t.project_id = {{project_id}} AND ts.category != 'done' AND t.deleted_at IS NULL
+GROUP BY pm.account_id, ac.name
+ORDER BY open_tasks DESC$new$,
+    updated_at = NOW()
+WHERE type IN ('chart', 'table')
+  AND regexp_replace(query, '\s+', ' ', 'g') = $old$SELECT COALESCE(NULLIF(u.full_name, ''), u.username, a.name, 'Unassigned') AS assignee, COUNT(DISTINCT t.id) AS open_tasks FROM tasks t JOIN task_statuses ts ON ts.id = t.status_id LEFT JOIN task_assignees ta ON ta.task_id = t.id LEFT JOIN project_members pm ON pm.id = ta.member_id LEFT JOIN users u ON u.id = pm.user_id LEFT JOIN agents a ON a.id = pm.agent_id WHERE t.project_id = {{project_id}} AND ts.category != 'done' AND t.deleted_at IS NULL GROUP BY pm.id, u.full_name, u.username, a.name ORDER BY open_tasks DESC$old$;
diff --git a/frontend/src/presets.ts b/frontend/src/presets.ts
index ee3eff7..cd21c1e 100644
--- a/frontend/src/presets.ts
+++ b/frontend/src/presets.ts
@@ -100,15 +100,14 @@ ORDER BY task_count DESC`,
     panelType: "chart",
     chartType: "bar",
     scopes: ["project", "integration"],
-    query: `SELECT COALESCE(NULLIF(u.full_name, ''), u.username, a.name, 'Unassigned') AS assignee, COUNT(DISTINCT t.id) AS open_tasks
+    query: `SELECT COALESCE(ac.name, 'Unassigned') AS assignee, COUNT(DISTINCT t.id) AS open_tasks
 FROM tasks t
 JOIN task_statuses ts ON ts.id = t.status_id
 LEFT JOIN task_assignees ta ON ta.task_id = t.id
 LEFT JOIN project_members pm ON pm.id = ta.member_id
-LEFT JOIN users u ON u.id = pm.user_id
-LEFT JOIN agents a ON a.id = pm.agent_id
+LEFT JOIN accounts ac ON ac.id = pm.account_id
 WHERE t.project_id = {{project_id}} AND ts.category != 'done' AND t.deleted_at IS NULL
-GROUP BY pm.id, u.full_name, u.username, a.name
+GROUP BY pm.account_id, ac.name
 ORDER BY open_tasks DESC`,
   },
   {