spring security error Caused by: org.attoparser.ParseException: Exception evaluating SpringEL expression: s

Question

Caused by: org.attoparser.ParseException: Exception evaluating SpringEL expression: "#authentication.principal.username + '님'" (template: "test/fragments/nav" - line 10, col 57)

-->

    <!--        <a th:if="${#authentication.isAuthenticated()}" th:text="${#authentication.principal.username + '님'}"></a>-->

I tried both

It's displayed well when logged in, but an error appears when you log out