Can't import grails.plugin.springsecurity.annotation in Grails 3? - grails

Question

I've been following Burt Beckwith's tutorial on Spring Security for Grails 3. I installed the plugin build.gradle as it said in the tutorial, and ran s2-quickstart, which seems to work fine. The project compiles without complaint.
However when I try the import statement
import grails.plugin.springsecurity.annotation.Secured
the import isn't recognized and won't build, with error
Error:(2, 1) Groovyc: unable to resolve class grails.plugin.springsecurity.annotation.Secured
What's missing?
dependencies section of build.gradle:
dependencies {
compile "org.springframework.boot:spring-boot-starter-logging"
compile "org.springframework.boot:spring-boot-autoconfigure"
compile "org.grails:grails-core"
compile "org.springframework.boot:spring-boot-starter-actuator"
compile "org.springframework.boot:spring-boot-starter-tomcat"
compile "org.grails:grails-dependencies"
compile "org.grails:grails-web-boot"
compile "org.grails.plugins:cache"
compile "org.grails.plugins:scaffolding"
compile "org.grails.plugins:hibernate4"
compile "org.hibernate:hibernate-ehcache"
compile 'org.grails.plugins:spring-security-core:3.1.1' //***
console "org.grails:grails-console"
profile "org.grails.profiles:web"
runtime "com.bertramlabs.plugins:asset-pipeline-grails:2.8.2"
runtime "com.h2database:h2"
testCompile "org.grails:grails-plugin-testing"
testCompile "org.grails.plugins:geb"
testRuntime "org.seleniumhq.selenium:selenium-htmlunit-driver:2.47.1"
testRuntime "net.sourceforge.htmlunit:htmlunit:2.18"

Answer 1

I was able to resolve this issue in IntelliJ by clicking the "refresh" icon in the View \ Tools \ Gradle window.