title: Why am I getting an error "Object literal may only specify known properties"?
body: <p>I just upgraded from TypeScript 1.5 to the latest and I'm seeing an error in my code:</p>
  
  <pre><code>interface Options {
     /* ... others ... */
     callbackOnLocationHash?: boolean;
  }
  
  function f(opts: Options) { /* ... */ }
  
  //  Error: Object literal may only specify known properties,
  //     and 'callbackOnLoactionHash'does not exist in type 'Options'.
  f( { callbackOnLoactionHash: false });
  </code></pre>
  
  <p>Code looks fine to me. What's wrong?</p>
  
  <p>(Alternative universe version: I recognize the typo, and I really did mean to write that. What should I do to remove the error?)</p>