title: Errro running ng serve - module has no exported member
body: <p>Something has gotten misconfigured in my app.  I've returned to a commit which I know was working before the "incident", but I get errors when running <code>ng serve</code> (listed below) and the app fails to load.  The errors refer to files in <code>node_modules</code> which I do not edit.  I have tried <code>npm uninstall</code> followed by <code>npm install</code> for the modules <code>@angular/common</code> and <code>@angular/forms</code> but this has no effect.  At this point I don't know what to do.</p>
  
  <pre><code>[default] Checking started in a separate process...
  
  [default] /Users/carlson/dev/a2/manuscripta2b/node_modules/@angular/common/src/common.d.ts:19:10 
      Module '"/Users/carlson/dev/a2/manuscripta2b/node_modules/@angular/core/index"' has no exported member 'Version'.
  
  [default] /Users/carlson/dev/a2/manuscripta2b/node_modules/@angular/common/src/version.d.ts:13:10 
      Module '"/Users/carlson/dev/a2/manuscripta2b/node_modules/@angular/core/index"' has no exported member 'Version'.
  
  [default] /Users/carlson/dev/a2/manuscripta2b/node_modules/@angular/forms/src/version.d.ts:13:10 
      Module '"/Users/carlson/dev/a2/manuscripta2b/node_modules/@angular/core/index"' has no exported member 'Version'.
  [default] /Users/carlson/dev/a2/manuscripta2b/src/app/editor/editor/editor/editor.component.ts:23:14 
  </code></pre>