title: Extension 'eslint' is configured as formatter but it cannot format 'JavaScript'-files
body: <p>I am experiencing an intermittent problem with ESLint in VS Code. When saving a file, instead of formatting it, this message shows in the status bar:</p>
  <p><a href="https://i.stack.imgur.com/H5rlA.png" rel="noreferrer"><img src="https://i.stack.imgur.com/H5rlA.png" alt="enter image description here" /></a></p>
  <p>Apparently no one has ever reported this message on Google.</p>
  <p>When I say it is intermittent, it was working fine, then the computer (MBP) crashed, and on restarting this is the situation. It has happened previously, but I don't recall what I did to fix it.</p>
  <p>The app is a fairly complex Vue-based app based on a pre-configured template. In package.json:</p>
  <pre><code>    &quot;@vue/cli-plugin-eslint&quot;: &quot;^4.5.13&quot;,
  
      &quot;babel-eslint&quot;: &quot;^10.1.0&quot;,
      &quot;eslint&quot;: &quot;^7.31.0&quot;,
      &quot;eslint-plugin-import&quot;: &quot;^2.23.4&quot;,
      &quot;eslint-plugin-vue&quot;: &quot;^7.14.0&quot;,
  </code></pre>
  <p>In the VS Code workspace file:</p>
  <pre><code>        &quot;editor.codeLens&quot;: true,
          &quot;eslint.format.enable&quot;: true,
          &quot;editor.codeActionsOnSave&quot;: {
            &quot;source.fixAll.eslint&quot;: true,
          },
          &quot;[javascript]&quot;: {
              &quot;editor.defaultFormatter&quot;: &quot;dbaeumer.vscode-eslint&quot;
          },
          &quot;[vue]&quot;: {
              &quot;editor.defaultFormatter&quot;: &quot;dbaeumer.vscode-eslint&quot;
          },
          &quot;eslint.validate&quot;: [
              &quot;javascript&quot;
          ],
          &quot;debug.javascript.usePreview&quot;: true,
          &quot;debug.javascript.usePreviewAutoAttach&quot;: true,
          &quot;[jsonc]&quot;: {
              &quot;editor.defaultFormatter&quot;: &quot;dbaeumer.vscode-eslint&quot;
          },
  </code></pre>
  <p>I'm really not sure how to proceed to understand why vscode-eslint is reporting that it can't format JavaScript files.</p>
  <p>EDIT</p>
  <p><a href="https://github.com/microsoft/vscode-eslint/issues/1355" rel="noreferrer">This issue</a> regarding TypeScript gives some hints. It seems this error can result when the ESLint server is restarting or the extension host is under a lot of stress.</p>
  <p>In my project now, most files are formatting fine, although one consistently fails. That file is called <code>eslint.js</code> and is part of a build process, running eslint - I don't totally understand the configuration. I suspect that saving this file somehow causes eslint to be run/reloaded, and while that is happening, eslint-vscode tries to also run it and fails.</p>