检查是否正确配置了Spring Security，并且在代码中正确地调用了AuthenticationManager.authenticate方法。以下是一个示例代码：

@Configuration @EnableWebSecurity public class SecurityConfig extends WebSecurityConfigurerAdapter {

@Autowired
private UserDetailsService userDetailsService;

@Override
protected void configure(AuthenticationManagerBuilder auth) throws Exception {
    auth.userDetailsService(userDetailsService);
}

@Override
protected void configure(HttpSecurity http) throws Exception {
    http.authorizeRequests()
        .anyRequest().authenticated()
        .and()
        .formLogin().permitAll()
        .and()
        .logout().permitAll();
}

@Bean
public PasswordEncoder passwordEncoder() {
    return new BCryptPasswordEncoder();
}

}

@Controller public class LoginController {

@Autowired
private AuthenticationManager authenticationManager;

@Autowired
private JwtTokenUtil jwtTokenUtil;

@PostMapping("/login")
public ResponseEntity login(@RequestBody LoginRequest loginRequest) {

    Authentication authentication = authenticationManager.authenticate(
            new UsernamePasswordAuthenticationToken(loginRequest.getUsername(), loginRequest.getPassword()));

    SecurityContextHolder.getContext().setAuthentication(authentication);

    final UserDetails userDetails = userDetailsService
            .loadUserByUsername(loginRequest.getUsername());

    final String token = jwtTokenUtil.generateToken(userDetails);

    return ResponseEntity.ok(new LoginResponse(token));
}

}

在上面的示例代码中，我们将AuthenticationManager注入到LoginController中，并在login方法中正确地调用了AuthenticationManager.authenticate方法。同时，我们还需要在WebSecurityConfigurerAdapter中配置AuthenticationManager。