Im trying to generate android apk from my ionic project but i faced with this error:
can anyone help me?
My ionic info is:
@ionic/cli-utils : 1.19.2
ionic (Ionic CLI) : 3.20.0
global packages:
cordova (Cordova CLI) : 8.0.0
local packages:
@ionic/app-scripts : 3.1.8
Cordova Platforms : android 7.1.0
Ionic Framework : ionic-angular 3.9.2
System:
Android SDK Tools : 26.0.2
Node : v8.10.0
npm : 4.6.1
OS : Windows 8.1
Environment Variables:
ANDROID_HOME : F:\sdk
Misc:
backend : pro
///////////////////////////////////
And 
Installed platforms:
android 7.1.0
////////////////////////////////////////////////
And my build.gradle file is also:
buildscript {
repositories {
jcenter()
maven {
url “https://maven.google.com”
}
}
dependencies {
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
classpath 'com.android.tools.build:gradle:3.0.1'
}
}
allprojects {
repositories {
jcenter()
maven {
url “https://maven.google.com”
}
}
//This replaces project.properties w.r.t. build settings
project.ext {
defaultBuildToolsVersion=“27.0.1” //String
defaultMinSdkVersion=19 //Integer - Minimum requirement is Android 4.4
defaultTargetSdkVersion=27 //Integer - We ALWAYS target the latest by default
defaultCompileSdkVersion=27 //Integer - We ALWAYS compile with the latest by default
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}