Good morning

I have a problem 
"**com.android.volley.ServerError**"

This is my `build.gradle` file 'app'

```
apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "com.example.azizsana.espacemembre2"
        minSdkVersion 15
        targetSdkVersion 26
        multiDexEnabled true
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation project(':volley')
    implementation 'com.mcxiaoke.volley:library:1.0.19'
    implementation 'com.android.support:design:26.1.0'
    implementation 'com.android.support:support-annotations:27.1.1'
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

```

File: `build.gradle` Project:

```
// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {

    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'

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

allprojects {
    repositories {
        google()
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

```

In logcat, i see "

Failed to find layer 

`(com.example.azizsana.espacemembre2/com.example.azizsana.espacemembre2.RegisterActivity#0) in layer parent (no-parent).`