Android Studio design view error

Hi,

I am getting this error when i switch to design view.

Rendering failed with a known bug. Please try a rebuild. The following classes could not be instantiated: - android.support.constraint.ConstraintLayout (Open Class, Show Exception, Clear Cache) Tip: Use View.isInEditMode() in your custom views to skip code or show sample data when shown in the IDE. If this is an unexpected error you can also try to build the project, then manually refresh the layout.

Here is my gradle file, am i doing anything wrong?

apply plugin: 'com.android.application'

android { compileSdkVersion 26 buildToolsVersion "26.0.0" defaultConfig { applicationId "com.ol_digital.campusbiometricsystem" minSdkVersion 15 targetSdkVersion 26 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'
})




compile 'com.android.support:appcompat-v7:26.0.0'
compile 'com.android.support.constraint:constraint-layout:1.0.2'

compile('com.mikepenz:materialdrawer:5.9.5@aar') {
    transitive = true
}
compile 'com.mikepenz:google-material-typeface:3.0.1.1.original@aar'
compile 'com.mikepenz:fontawesome-typeface:4.7.0.1@aar'

compile 'com.github.alamkanak:android-week-view:1.2.6'

testCompile 'junit:junit:4.12'

}