title: How to fix java.lang.UnsupportedClassVersionError: test (class file version 52.65535) was compiled with preview features that are unsupported?
body: <p>I recieved this error when I trying to debug a java program with vscode:</p>
  
  <pre><code>java.lang.UnsupportedClassVersionError: 
  test (class file version 52.65535) was compiled with preview features that are unsupported. 
  This version of the Java Runtime only recognizes preview features for class file version 55.65535
  </code></pre>
  
  <p>Here is launch.json:</p>
  
  <pre><code>{
      "version": "0.2.0",
      "configurations": [
          {
              "type": "java",
              "name": "Debug (Launch) - Current File",
              "request": "launch",
              "mainClass": "${file}"
          },
          {
              "type": "java",
              "name": "Debug (Launch)-test",
              "request": "launch",
              "mainClass": "test"
          }
      ]
  }
  </code></pre>
  
  <p>Here is the version of java:</p>
  
  <pre><code>java --version:
  openjdk 11.0.2 2019-01-15
  OpenJDK Runtime Environment (build 11.0.2+9-Ubuntu-3ubuntu118.04.2)
  OpenJDK 64-Bit Server VM (build 11.0.2+9-Ubuntu-3ubuntu118.04.2, mixed mode, sharing)
  
  javac --version:
  javac 11.0.2
  </code></pre>
  
  <p>This program can run on ubuntu original terminal, but throws error in vscode.</p>
  
  <p>it would be greatful if you can help me out.</p>