diff --git a/src/plugins/registry.ts b/src/plugins/registry.ts
index 2a3055d45fb..0f8909c713c 100644
--- a/src/plugins/registry.ts
+++ b/src/plugins/registry.ts
@@ -319,12 +319,15 @@ const canonicalizePluginMainSessionAlias = (params: {
 };
 
 const resolveDefaultPluginAgentId = (cfg: OpenClawConfig): string => {
-  const agents = Array.isArray(cfg.agents?.list) ? cfg.agents.list : [];
-  const preferred =
-    agents.find((agent) => agent?.default)?.id ??
-    agents.find((agent) => typeof agent?.id === "string")?.id ??
-    FALLBACK_AGENT_ID;
-  return normalizePluginAgentId(preferred);
+  const agents = Array.isArray(cfg.agents?.list)
+    ? cfg.agents.list.filter((agent) => Boolean(agent && typeof agent === "object"))
+    : [];
+  if (agents.length === 0) {
+    return FALLBACK_AGENT_ID;
+  }
+  const preferredEntry = agents.find((agent) => agent?.default) ?? agents[0];
+  const preferredId = typeof preferredEntry?.id === "string" ? preferredEntry.id : undefined;
+  return normalizePluginAgentId(preferredId);
 };
 
 const resolvePluginMainSessionKey = (cfg: OpenClawConfig): string => {