In addition to the changes provided by Mohamed, I also needed to change my request matcher.

@Bean
public RequestMatcher requestMatcher() {
    // if (!swagger && !error) then apply CustomAuthenticationFilter
    return new NegatedRequestMatcher(new OrRequestMatcher(Arrays.asList(
        new AntPathRequestMatcher("/api-docs/**"),
        new AntPathRequestMatcher("/error")
    )));
}