title: Facebook API returns "Invalid OAuth access token signature."
body: <p>For my website I use the Facebook API to get the events from a few Facebook pages. For this purpose I have created a Facebook app.</p>
  
  <p>However, even though this used to work before, the API now returns an error: </p>
  
  <pre><code>"message": "Invalid OAuth access token signature.",
  "type":"OAuthException",
  "code": 190,
  </code></pre>
  
  <p>Here are the steps to reproduce the error:</p>
  
  <ol>
  <li><p>Go to app's dashboard on <a href="https://developers.facebook.com/apps" rel="nofollow noreferrer">https://developers.facebook.com/apps</a></p></li>
  <li><p>Get the app id (APP_ID) and the app secret (APP_SECRET)</p></li>
  <li><p>Use the app id and the app secret to get an access token by using this url: </p>
  
  <p><a href="https://graph.facebook.com/oauth/access_token?client_id=APP_ID" rel="nofollow noreferrer">https://graph.facebook.com/oauth/access_token?client_id=APP_ID</a>
  &amp;client_secret=APP_SECRET&amp;grant_type=client_credentials</p></li>
  <li><p>This returns something like</p>
  
  <p>{"access_token":"123412342134|f34f34f32fc3rc4rc324r-X","token_type":"bearer"}</p></li>
  <li><p>I then use this access token to access the events</p>
  
  <p><a href="https://graph.facebook.com/v2.12/" rel="nofollow noreferrer">https://graph.facebook.com/v2.12/</a>{11239244970}/events/?fields={id,name}&amp;access_token={123412342134|f34f34f32fc3rc4rc324r-X}</p></li>
  <li><p>However, this returns the error mentioned above, "Invalid OAuth access token signature.".</p></li>
  </ol>
  
  <p>I'm stuck here. None of the posts on here seem to solve my problem. </p>
  
  <p>I've already tried resetting the app secret, but that didn't help. Any hints are greatly appreciated!</p>