diff --git a/lib/membership/setting.ex b/lib/membership/setting.ex
index 13e7411..602eab9 100644
--- a/lib/membership/setting.ex
+++ b/lib/membership/setting.ex
@@ -152,10 +152,23 @@ defmodule Mv.Membership.Setting do
                    {:ok, _} ->
                      :ok
 
-                   {:error, _} ->
+                   {:error, %Ash.Error.Invalid{errors: [%Ash.Error.Query.NotFound{} | _]}} ->
                      {:error,
                       field: :default_membership_fee_type_id,
                       message: "Membership fee type not found"}
+
+                   {:error, err} ->
+                     # Log unexpected errors (DB timeout, connection errors, etc.)
+                     require Logger
+
+                     Logger.warning(
+                       "Unexpected error when validating default_membership_fee_type_id: #{inspect(err)}"
+                     )
+
+                     # Return generic error to user
+                     {:error,
+                      field: :default_membership_fee_type_id,
+                      message: "Could not validate membership fee type"}
                  end
                else
                  # Optional, can be nil