2018.2: Unsupported Modules Detected

After I upgrade IDEA to 2018.2 from 2018.1.6, it shows "Unsupported Modules Detected: Compilation is not supported for following modules: main, test. Unfortunately you can't have non-Gradle Java modules and Android-Gradle modules in one project."

But my project is a full spring boot project, I've never created android module.

How to fix it?

my project structure:

My build.gradle:

plugins {
 id 'org.springframework.boot' version '2.0.3.RELEASE'
 id "org.owasp.dependencycheck" version "3.2.1"
 id "com.github.jk1.dependency-license-report" version "0.8"
 id 'com.github.psxpaul.execfork' version '0.1.7'
}

apply plugin: 'java'
apply plugin: 'findbugs'
apply plugin: 'io.spring.dependency-management'

task wrapper(type: Wrapper) {
 gradleVersion = '4.7'
}

repositories {
 mavenCentral()
 jcenter()
}

dependencies {
 /**
 * COMPILE DEPENDENCIES
 */
 compile "org.projectlombok:lombok:1.16.18" // requires annotation processors to be enabled in IDE

 compile("org.springframework.boot:spring-boot-starter-web")
 compile("org.springframework.boot:spring-boot-starter-security")
 compile("io.jsonwebtoken:jjwt:0.9.0")
 compile("org.springframework.boot:spring-boot-starter-actuator")
 compile('org.springframework.boot:spring-boot-starter-data-jpa')
 compile('org.springframework.boot:spring-boot-starter-json')
 compile("org.springframework.boot:spring-boot-starter-mail")
 compile("org.springframework.boot:spring-boot-starter-thymeleaf")

 // AWS related dependencies
 compile 'com.amazonaws:aws-java-sdk-s3:1.11.363'
 compile 'com.amazonaws:aws-java-sdk-sqs:1.11.363'

 // data access to DB via JPA & Spring Data
 compile 'org.postgresql:postgresql:42.2.2' // PostgreSQL driver
 compile "org.flywaydb:flyway-core:5.0.7" // DB migrations
 
 // Swagger 2 OpenAPI documentation
 compile 'io.springfox:springfox-swagger2:2.8.0'
 compile 'io.springfox:springfox-swagger-ui:2.8.0'

 // utilities liabraries
 compile("com.google.guava:guava:24.1-jre")
 compile 'org.apache.commons:commons-text:1.4'

 // Jersey REST client for integrations
 compile 'org.glassfish.jersey.core:jersey-client:2.27'
 compile group: 'org.glassfish.jersey.media', name: 'jersey-media-multipart', version: '2.27'

 // compatibility
 compile 'org.glassfish.jersey.inject:jersey-hk2:2.27'

 // security upgrade for individual denpendencies which had vulnebilities

 /**
 * RUNTIME DEPENDENCIES
 */

 // embedded Undertow web server for Spring Boot
 runtime("org.springframework.boot:spring-boot-starter-undertow")

 /**
 * TEST DEPENDENCIES
 */
 testCompile("org.springframework.boot:spring-boot-starter-test")
 testCompile("io.cucumber:cucumber-java:$cucumberVersion")
 testCompile("io.cucumber:cucumber-junit:$cucumberVersion")
 testCompile("org.junit.jupiter:junit-jupiter-api:5.2.0")
 testCompile("org.junit.jupiter:junit-jupiter-engine:5.2.0")
 // Bitbucket pipeline test result location
 test {
 reports.junitXml.destination = file('build/test-results/')
 }
}

// Spring Boot
bootJar {
 mainClassName = 'com.server.Application'
 launchScript()
}

compileJava {
 options.encoding = 'UTF-8'
 options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation"
}

// code quality
findbugs {
 effort = "max"
 reportLevel = "medium"
 includeFilter = file("$rootProject.projectDir/findBugsIncludeFilter.xml")
 excludeFilter = file("$rootProject.projectDir/findBugsExcludeFilter.xml")
}

tasks.withType(FindBugs) {
 reports {
 xml.enabled false
 html.enabled true
 }
}

// OWASP dep check & license check
apply plugin: 'org.owasp.dependencycheck'
apply plugin: "com.github.jk1.dependency-license-report"

dependencyCheck {
// cve {
// url20Modified = 'https://nvd.nist.gov/feeds/xml/cve/2.0/nvdcve-2.0-modified.xml.gz'
// url20Base = 'https://nvd.nist.gov/feeds/xml/cve/2.0/nvdcve-2.0-%d.xml.gz'
// }
 suppressionFile= "owasp-dependency-check-suppression.xml"
 format = "ALL"
 // fail if any vulneragbility with High Severity vulnerability appears
 // based on CVSS (Common Vulnerabilit Scoring System)
 // https://www.first.org/cvss/
 // https://www.first.org/cvss/specification-document#5-Qualitative-Severity-Rating-Scale
 failBuildOnCVSS = 6.9

}

licenseReport {
 renderers = new com.github.jk1.license.render.InventoryHtmlReportRenderer('third-party-license-report.html')
}