Plugin with id 'com.getkeepsafe.dexcount' not found

Just try to implement Dexcount plugin within my project, but for some reason is not working and I get the following error (details are below):

Plugin with id ‘com.getkeepsafe.dexcount’ not found

Code

apply plugin: 'com.android.application'
apply plugin: 'com.getkeepsafe.dexcount'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.0"
    defaultConfig {
        applicationId "com.packagename.customtoolbarwithsupportlibrary"
        minSdkVersion 21
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    classpath 'com.getkeepsafe.dexcount:dexcount-gradle-plugin:0.7.3'
    compile 'com.android.support:appcompat-v7:25.0.0'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    testCompile 'junit:junit:4.12'
}

[benjamin-bader]

This error is entirely unrelated to dexcount. At this point, I’d suggest taking your questions to stackoverflow.com.

[macaronlover]

After doing that I still get an error:

Error:Cause: buildToolsVersion is not specified

apply plugin: 'com.android.application'
apply plugin: 'com.getkeepsafe.dexcount'

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.3'

        classpath 'com.getkeepsafe.dexcount:dexcount-gradle-plugin:0.7.3'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}