title: How do I convert a libGDX GWT game to version 1.9.5?
body: <p>I am trying to upgrade my game to libGDX 1.9.5. The game works fine on desktop, but when I try to build the HTML version I get the following error:</p>
  
  <pre><code>Configuration on demand is an incubating feature.
  :core:compileJava UP-TO-DATE
  :core:processResources UP-TO-DATE
  :core:classes UP-TO-DATE
  :core:jar UP-TO-DATE
  :html:compileJava UP-TO-DATE
  :html:processResources UP-TO-DATE
  :html:classes UP-TO-DATE
  :html:addSource
  :html:compileGwt
  Loading inherited module 'tech.otter.merchant.GdxDefinition'
     Loading inherited module 'com.badlogic.gdx.backends.gdx_backends_gwt'
        Loading inherited module 'com.google.gwt.user.User'
           Loading inherited module 'com.google.gwt.media.Media'
              Loading inherited module 'com.google.gwt.user.UI'
                 Loading inherited module 'com.google.gwt.uibinder.UiBinder'
                    [ERROR] Line 20: Unexpected element 'resource'
                    [ERROR] Failure while parsing XML
  com.google.gwt.core.ext.UnableToCompleteException: (see previous log entries)
          at com.google.gwt.dev.util.xml.DefaultSchema.onUnexpectedElement(DefaultSchema.java:86)
  </code></pre>
  
  <p>Historically, the biggest challenges for me when using GWT have been VisUI and gdx-kiwi, but I have gone to their wikis and updated their versions in my gradle files shown below:</p>
  
  <p><strong>/build.gradle</strong></p>
  
  <pre><code>buildscript {
      repositories {
          mavenLocal()
          mavenCentral()
          maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
          jcenter()
      }
      dependencies {
          classpath 'de.richsource.gradle.plugins:gwt-gradle-plugin:0.6'
          classpath 'com.android.tools.build:gradle:2.2.0'
          classpath "com.badlogicgames.gdx:gdx-tools:1.9.4"
      }
  }
  
  allprojects {
      apply plugin: "eclipse"
      apply plugin: "idea"
  
      version = '1.1'
      ext {
          appName = "merchant"
          gdxVersion = '1.9.5'
          roboVMVersion = '2.2.0'
          box2DLightsVersion = '1.4'
          ashleyVersion = '1.7.0'
          aiVersion = '1.8.0'
          kiwiVersion = '1.8.1.9.4'
          visVersion = '1.3.0-SNAPSHOT'
      }
  
      repositories {
          mavenLocal()
          mavenCentral()
          maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
          maven { url "https://oss.sonatype.org/content/repositories/releases/" }
      }
  }
  
  project(":desktop") {
      apply plugin: "java"
  
      dependencies {
          compile project(":core")
          compile "com.badlogicgames.gdx:gdx-backend-lwjgl:$gdxVersion"
          compile "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-desktop"
          compile "com.badlogicgames.gdx:gdx-tools:$gdxVersion"
          compile "com.github.czyzby:gdx-kiwi:$kiwiVersion"
      }
  }
  
  project(":android") {
      apply plugin: "android"
  
      configurations { natives }
  
      dependencies {
          compile project(":core")
          compile "com.badlogicgames.gdx:gdx-backend-android:$gdxVersion"
          natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-armeabi"
          natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-armeabi-v7a"
          natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-arm64-v8a"
          natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-x86"
          natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-x86_64"
          compile "com.badlogicgames.gdx:gdx-ai:$aiVersion"
      }
  }
  
  project(":html") {
      apply plugin: "gwt"
      apply plugin: "war"
  
      dependencies {
          compile project(":core")
          compile "com.badlogicgames.gdx:gdx-backend-gwt:$gdxVersion"
          compile "com.badlogicgames.gdx:gdx:$gdxVersion:sources"
          compile "com.badlogicgames.gdx:gdx-backend-gwt:$gdxVersion:sources"
          compile "com.badlogicgames.gdx:gdx-ai:$aiVersion:sources"
          compile "com.github.czyzby:gdx-kiwi:$kiwiVersion:sources"
          compile "com.kotcrab.vis:vis-ui:$visVersion:sources"
      }
  }
  
  project(":core") {
      apply plugin: "java"
  
      dependencies {
          compile "com.badlogicgames.gdx:gdx:$gdxVersion"
          compile "com.badlogicgames.gdx:gdx-ai:$aiVersion"
          compile "com.github.czyzby:gdx-kiwi:$kiwiVersion"
          compile "com.kotcrab.vis:vis-ui:$visVersion"
      }
  }
  
  tasks.eclipse.doLast {
      delete ".project"
  }
  </code></pre>
  
  <p><strong>html/build.gradle</strong></p>
  
  <pre><code>apply plugin: "java"
  apply plugin: "jetty"
  
  gwt {
      gwtVersion='2.6.1' // Should match the gwt version used for building the gwt backend
      maxHeapSize="1G" // Default 256m is not enough for gwt compiler. GWT is HUNGRY
      minHeapSize="1G"
  
      src = files(file("src/")) // Needs to be in front of "modules" below.
      modules 'tech.otter.merchant.GdxDefinition'
      devModules 'tech.otter.merchant.GdxDefinitionSuperdev'
      project.webAppDirName = 'webapp'
  
      compiler {
          strict = true;
          enableClosureCompiler = true;
          disableCastChecking = true;
      }
  }
  
  task draftRun(type: JettyRunWar) {
      dependsOn draftWar
      dependsOn.remove('war')
      webApp=draftWar.archivePath
      daemon=true
  }
  
  task superDev(type: de.richsource.gradle.plugins.gwt.GwtSuperDev) {
      dependsOn draftRun
      doFirst {
          gwt.modules = gwt.devModules
      }
  }
  
  task dist(dependsOn: [clean, compileGwt]) {
      doLast {
          file("build/dist").mkdirs()
          copy {
              from "build/gwt/out"
              into "build/dist"
          }
          copy {
              from "webapp"
              into "build/dist"
              }
          copy {
              from "war"
              into "build/dist"
          }
          delete "../../madigan.github.io/merchant/"
          copy {
              from "build/dist"
              into "../../madigan.github.io/merchant/"
          }
          doGit
      }
  
  }
  
  task doGit(type: Exec) {
      commandLine 'git', '-C', '../../madigan.github.io', 'add', '.'
      commandLine 'git', '-C', '../../madigan.github.io', 'commit', '-m', '"Distribution."'
      commandLine 'git', '-C', '../../madigan.github.io', 'push'
  }
  
  draftWar {
     from "war"
  }
  
  task addSource &lt;&lt; {
      sourceSets.main.compileClasspath += files(project(':core').sourceSets.main.allJava.srcDirs)
  }
  
  tasks.compileGwt.dependsOn(addSource)
  tasks.draftCompileGwt.dependsOn(addSource)
  
  sourceCompatibility = 1.8
  sourceSets.main.java.srcDirs = [ "src/" ]
  
  
  eclipse.project {
      name = appName + "-html"
  }
  </code></pre>
  
  <p>Any advice or tips on how to troubleshoot this error would be much appreciated.</p>
  
  <p><strong>[EDIT]</strong></p>
  
  <p>I read the release notes a little closer, and it says that I should change the GWT version to 2.8.0. Even when I do this, I still get the following error:</p>
  
  <pre><code>Configuration on demand is an incubating feature.
  :core:compileJava UP-TO-DATE
  :core:processResources UP-TO-DATE
  :core:classes UP-TO-DATE
  :core:jar UP-TO-DATE
  :html:compileJava UP-TO-DATE
  :html:processResources UP-TO-DATE
  :html:classes UP-TO-DATE
  :html:addSource
  :html:compileGwt
  Unknown argument: -XenableClosureCompiler
  Google Web Toolkit 2.8.0
  Compiler [-logLevel (ERROR|WARN|INFO|TRACE|DEBUG|SPAM|ALL)] [-workDir dir] [-X[no]closureFormattedOutput] [-[no]compileReport] [-X[no]checkCasts] [-X[no]classMetadata] [-[no]draftCompile] [-[no]checkAssertions] [-XfragmentCount numFragments] [-XfragmentMerge numFragments] [-gen dir] [-[no]generateJsInteropExports] [-XmethodNameDisplayMode (NONE|ONLY_METHOD_NAME|ABBREVIATED|FULL)] [-Xnamespace (NONE|PACKAGE)] [-optimize level] [-[no]saveSource] [-setProperty name=value,value...] [-style (DETAILED|OBFUSCATED|PRETTY)] [-[no]failOnError] [-[no]validateOnly] [-sourceLevel [auto, 1.8]] [-localWorkers count] [-[no]incremental] [-war dir] [-deploy dir] [-extra dir] [-saveSourceOutput dir] module[s] 
  
  where 
    -logLevel                      The level of logging detail: ERROR, WARN, INFO, TRACE, DEBUG, SPAM or ALL (defaults to INFO)
    -workDir                       The compiler's working directory for internal use (must be writeable; defaults to a system temp dir)
    -X[no]closureFormattedOutput   EXPERIMENTAL: Enables Javascript output suitable for post-compilation by Closure Compiler (defaults to OFF)
    -[no]compileReport             Compile a report that tells the "Story of Your Compile". (defaults to OFF)
    -X[no]checkCasts               EXPERIMENTAL: DEPRECATED: use jre.checks.checkLevel instead. (defaults to OFF)
    -X[no]classMetadata            EXPERIMENTAL: Include metadata for some java.lang.Class methods (e.g. getName()). (defaults to ON)
    -[no]draftCompile              Compile quickly with minimal optimizations. (defaults to OFF)
    -[no]checkAssertions           Include assert statements in compiled output. (defaults to OFF)
    -XfragmentCount                EXPERIMENTAL: Limits of number of fragments using a code splitter that merges split points.
    -XfragmentMerge                DEPRECATED (use -XfragmentCount instead): Enables Fragment merging code splitter.
    -gen                           Debugging: causes normally-transient generated types to be saved in the specified directory
    -[no]generateJsInteropExports  Generate exports for JsInterop purposes (defaults to OFF)
    -XmethodNameDisplayMode        EXPERIMENTAL: Specifies method display name mode for chrome devtools: NONE, ONLY_METHOD_NAME, ABBREVIATED or FULL (defaults to NONE)
    -Xnamespace                    Puts most JavaScript globals into namespaces. Default: PACKAGE for -draftCompile, otherwise NONE
    -optimize                      Sets the optimization level used by the compiler.  0=none 9=maximum.
    -[no]saveSource                Enables saving source code needed by debuggers. Also see -debugDir. (defaults to OFF)
    -setProperty                   Set the values of a property in the form of propertyName=value1[,value2...].
    -style                         Script output style: DETAILED, OBFUSCATED or PRETTY (defaults to OBFUSCATED)
    -[no]failOnError               Fail compilation if any input file contains an error. (defaults to ON)
    -[no]validateOnly              Validate all source code, but do not compile. (defaults to OFF)
    -sourceLevel                   Specifies Java source level (defaults to 1.8)
    -localWorkers                  The number of local workers to use when compiling permutations
    -[no]incremental               Compiles faster by reusing data from the previous compile. (defaults to OFF)
    -war                           The directory into which deployable output files will be written (defaults to 'war')
    -deploy                        The directory into which deployable but not servable output files will be written (defaults to 'WEB-INF/deploy' under the -war directory/jar, and may be the same as the -extra directory/jar)
    -extra                         The directory into which extra files, not intended for deployment, will be written
    -saveSourceOutput              Overrides where source files useful to debuggers will be written. Default: saved with extras.
  and 
    module[s]                      Specifies the name(s) of the module(s) to compile
  :html:compileGwt FAILED
  </code></pre>
  
  <p><strong>[EDIT #2]</strong></p>
  
  <p>Now that the flag is removed per @Colin Altworth's answer, I get the following error particular to vis-ui (again, updated to use the recommended version for libGDX 1.9.5):</p>
  
  <pre><code>:html:compileGwt
  Compiling module tech.otter.merchant.GdxDefinition
     Tracing compile failure path for type 'com.kotcrab.vis.ui.util.async.AsyncTask'
        [ERROR] Errors in 'jar:file:/home/john/.gradle/caches/modules-2/files-2.1/com.kotcrab.vis/vis-ui/1.3.0-SNAPSHOT/e5f8abbdc3524212158f65d63c9a28d226795f97/vis-ui-1.3.0-SNAPSHOT-sources.jar!/com/kotcrab/vis/ui/util/async/AsyncTask.java'
           [ERROR] Line 46: The constructor Thread(new Runnable(){}, String) is undefined
           [ERROR] Line 51: The method start() is undefined for the type Thread
     [ERROR] Aborting compile due to errors in some input files
  :html:compileGwt FAILED
  
  FAILURE: Build failed with an exception.
  </code></pre>
  
  <p><strong>[EDIT #3]</strong></p>
  
  <p>Turns out the rest of the issue was a bug in VisUI- the latest update tries to use the Thread class, which is not supported by GWT.</p>