Android Gradle Sync failed could not find support-core-ui.aar : <p>I've been working on this Android Project for about a year now, suddenly when I opened it yesterday Android Studio 3.1.2 failed to sync gradle and the project doesn't build anymore giving me this error:</p>

<pre><code>Could not find support-core-ui.jar (com.android.support:support-core-ui:27.1.1).
    Searched in the following locations:
        https://jcenter.bintray.com/com/android/support/support-core-ui/27.1.1/support-core-ui-27.1.1.jar

    Please install the Android Support Repository from the Android SDK Manager.
    Open Android SDK Manager
</code></pre>

<p>I'm pretty sure that the Android Support Repository is installed correctly because it's working successfully in other projects and all my other projects are working fine with no problems.</p>

<p>I have this gradle file in the app module:</p>

<pre><code>buildscript {
    repositories {
        maven { url 'https://maven.fabric.io/public' }
    }
    dependencies {
        classpath 'io.fabric.tools:gradle:1.21.5'
    }
}
plugins {
    id 'com.onesignal.androidsdk.onesignal-gradle-plugin' version '0.8.1'
}
apply plugin: 'com.onesignal.androidsdk.onesignal-gradle-plugin'
apply plugin: 'com.android.application'
apply plugin: 'io.fabric'
apply plugin: 'com.neenbedankt.android-apt'
apply plugin: 'realm-android'

android {
    compileSdkVersion 27
    buildToolsVersion "27.0.3"

    defaultConfig {
        minSdkVersion 16
        targetSdkVersion 23
        versionCode 32
        versionName "3.1"

        multiDexEnabled true

        manifestPlaceholders = [onesignal_app_id               : "",
                                // Project number pulled from dashboard, local value is ignored.
                                onesignal_google_project_number: "REMOTE"]

    }

    configurations {
        all*.exclude group: 'com.android.support', module: 'support-v4'
    }

    configurations.all {
        resolutionStrategy.eachDependency { DependencyResolveDetails details -&gt;
            def requested = details.requested
            if (requested.group == 'com.android.support') {
                if (!requested.name.startsWith("multidex")) {
                    details.useVersion '27.1.1'
                }
            }
            if (requested.group == 'com.google.android.gms') {
                details.useVersion '15.0.1'
            }
            if (requested.group == 'com.google.firebase') {
                details.useVersion '15.0.1'
            }
        }
    }

    buildTypes {
        release {
            minifyEnabled false
//            proguardFiles 'proguard.cfg'
        }
    }

    useLibrary 'org.apache.http.legacy'
    packagingOptions {
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/NOTICE.txt'
        exclude 'META-INF/DEPENDENCIES'
    }
}

repositories {
    maven {
        url "https://jitpack.io"
    }
    maven {
        url  "https://dl.bintray.com/lukaville/maven"
    }
    maven { url 'https://maven.fabric.io/public' }
    maven { url 'https://maven.google.com' }
    mavenCentral()
}

dependencies {
    compile project(':FORTSDKv1.4.1')
    compile files('libs/nineoldandroids-2.4.0.jar')
    compile files('libs/gcm.jar')
    compile files('libs/httpclient-4.3.4.jar')
    compile files('libs/httpmime-4.2.5.jar')
    compile files('libs/HockeySDK-3.0.2.jar')
    compile files('libs/samsungpay-1.8.00.jar')
    compile project(':library-2.4.1')
    // Required for geotagging
    compile('com.crashlytics.sdk.android:crashlytics:2.6.8@aar') {
        transitive = true
    }
    compile('com.code-troopers.betterpickers:library:3.1.0') {
        exclude group: 'com.nineoldandroids', module: 'library'
    }
    compile 'com.android.support:support-v4:27.0.0'
    // https://mvnrepository.com/artifact/com.android.support/support-core-ui
    compile group: 'com.android.support', name: 'support-core-ui', version: '27.1.1'
    compile 'com.android.support:appcompat-v7:27.0.0'
    compile 'com.android.support:cardview-v7:27.0.0'
    compile 'com.android.support:customtabs:27.0.0'
    compile 'com.android.support:multidex:1.0.3'
    compile 'com.googlecode.libphonenumber:libphonenumber:8.8.9'
    compile 'org.parceler:parceler-api:1.1.5'
    compile('com.google.android.gms:play-services-analytics:11.8.0') {
        exclude group: 'com.android.support', module: 'support-v4'
    }
    compile 'com.google.android.gms:play-services-maps:15.0.1'
    compile 'com.google.android.gms:play-services-auth:15.0.1'
    compile 'com.google.android.gms:play-services-gcm:15.0.1'
    compile 'com.google.android.gms:play-services-location:15.0.1'
    //    compile 'com.google.android.gms:play-services-analytics:11.8.0'
    compile 'com.github.hackware1993:MagicIndicator:1.5.0'
    compile 'com.roomorama:caldroid:2.3.1'
    compile 'com.google.code.gson:gson:2.8.1'
    compile 'com.leocardz:aelv:1.1@aar'
    compile 'com.flaviofaria:kenburnsview:1.0.7'
    compile('com.jakewharton:butterknife:8.4.0') {
        exclude module: 'support-compat'
        exclude group: 'com.google.android', module: 'support-v4'
    }
    compile 'com.pixplicity.easyprefs:library:1.8.1@aar'
    compile 'de.hdodenhof:circleimageview:2.2.0'
    compile 'com.github.jrvansuita:IconHandler:+'
    compile 'com.github.mancj:SlideUp-Android:2.2.5'
    compile 'com.afollestad:sectioned-recyclerview:0.5.0'
    compile 'com.github.bumptech.glide:glide:3.7.0'
    compile 'com.facebook.stetho:stetho:1.4.1'
    compile 'com.facebook.stetho:stetho-okhttp3:1.4.1'
    compile 'com.uphyca:stetho_realm:2.0.0'
    compile 'org.greenrobot:eventbus:3.1.1'
    compile 'com.birbit:android-priority-jobqueue:2.0.1'
    compile 'com.squareup.retrofit2:retrofit:2.3.0'
    compile 'com.squareup.retrofit2:converter-gson:2.1.0'
    compile 'com.squareup.retrofit2:converter-scalars:2.1.0'
    compile 'com.valdesekamdem.library:md-toast:0.8.0'
    compile 'com.facebook.android:account-kit-sdk:4.30.0'
    compile 'com.facebook.android:facebook-android-sdk:4.17.0'
    compile 'com.wang.avi:library:2.1.3@aar'
    compile 'com.afollestad.material-dialogs:core:0.9.6.0'
    //    compile 'com.onesignal:OneSignal:3.6.5'
    compile 'com.onesignal:OneSignal:[3.9.1, 3.99.99]'
    compile 'com.kbeanie:image-chooser-library:1.6.0@aar'
    compile 'com.squareup.picasso:picasso:2.5.2'
    compile 'com.scalified:fab:1.1.3'
    compile 'com.github.traex.expandablelayout:library:1.2.2'
    compile 'com.github.markomilos:paginate:0.5.1'
    compile 'com.wdullaer:materialdatetimepicker:3.3.0'
    compile 'com.github.tamir7.contacts:contacts:1.1.7'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    compile 'net.yslibrary.keyboardvisibilityevent:keyboardvisibilityevent:2.1.0'
    compile 'com.github.livechat:chat-window-android:v2.0.0'
    compile 'com.uber.sdk:rides-android:0.6.1'
    compile 'link.fls:swipestack:0.3.0'
    compile 'com.github.PhilJay:MPAndroidChart:v3.0.2'
    compile 'com.victor:lib:1.0.1'
    compile 'com.shamanland:fonticon:0.1.8'
    compile 'jp.wasabeef:recyclerview-animators:2.2.7'
    compile 'com.squareup.okhttp3:logging-interceptor:3.8.0'
    compile 'com.github.vihtarb:tooltip:0.1.9'
    compile 'com.daasuu:CountAnimationTextView:0.1.1'
    compile 'com.theartofdev.edmodo:android-image-cropper:2.5.1'
    compile('com.android.billingclient:billing:1.0') {
        exclude module: 'support-compat'
        exclude group: 'com.google.android', module: 'support-v4'
    }
    compile('de.keyboardsurfer.android.widget:crouton:1.8.5@aar') {
        // exclusion is not necessary, but generally a good idea.
        exclude group: 'com.google.android', module: 'support-v4'
    }
    compile 'com.nbsp:library:1.8'
    apt 'com.jakewharton:butterknife-compiler:8.8.1'
    apt 'org.parceler:parceler:1.1.5'
    compile 'com.google.guava:guava:19.0'
    compile 'org.bouncycastle:bcprov-jdk16:1.46'
}


apply plugin: 'com.google.gms.google-services'
</code></pre>

<p>Any suggestions or solutions are very appreciated. Thanks.</p>
