title: Gradle Build Error java.lang.IllegalArgumentException
body: <p>I'm getting a grade build error when i want to launch my project. It goes like that:</p>
  
  <pre><code>Error:Execution failed for task ':app:processDebugResources'.
  &gt; java.lang.IllegalArgumentException (no error message)
  </code></pre>
  
  <p>I copy pasted some stuff into this project, which caused a few errors before, so it might be an error because of copy/pasting... </p>
  
  <p>Here is my build.grade files:</p>
  
  <pre><code>buildscript {
      repositories {
          jcenter()
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:2.3.3'
      }
  }
  
  allprojects {
      repositories {
          jcenter()
      }
  }
  
  task clean(type: Delete) {
      delete rootProject.buildDir
  }
  </code></pre>
  
  <p>and another build.gradle file:</p>
  
  <pre><code>    apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 26
      buildToolsVersion "26.0.2"
      defaultConfig {
          applicationId "com.example.leodr.upgradeadmin"
          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(include: ['*.jar'], dir: 'libs')
      androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
          exclude group: 'com.android.support', module: 'support-annotations'
      })
      compile files('libs/gson-1.4.jar')
      compile 'com.android.support:appcompat-v7:26.+'
      compile 'com.android.support.constraint:constraint-layout:1.0.2'
      testCompile 'junit:junit:4.12'
  }
  </code></pre>
  
  <p>I hope you can help me, TY for your help!</p>