How to fix Duplicate Facebook pixel ID error?

Added facebook pixel like they showed here here Now getting an error:

fbevents.js:9 Facebook Pixel Error: Duplicate Pixel ID: some-pixel-id

Cannot understand what causes this error. Even when I run the code from their example with removed pixel code from html in the console I get the same result.

Anyone knows what that means and how to solve this error ?

I found the solution on this page actually.

Its because everytime you send an event the code is initialized with the same pixel id. Actually initialization should happen only once."

This fix works. You can verify that by using the Facebook Pixel Helper as an extension in Chrome.

if(typeof fbq === 'undefined') {
    !function(f,b,e,v,n,t,s){if(f.fbq)return;n=f.fbq=function(){n.callMethod?
    n.callMethod.apply(n,arguments):n.queue.push(arguments)};if(!f._fbq)f._fbq=n;
    n.push=n;n.loaded=!0;n.version='2.0';n.queue=[];t=b.createElement(e);t.async=!0;
    t.src=v;s=b.getElementsByTagName(e)[0];s.parentNode.insertBefore(t,s)}(window,
    document,'script','https://connect.facebook.net/en_US/fbevents.js');

    fbq('init', '123123123213121');
    fbq('track', 'PageView');
    fbq('track', '{{fBPixelType}}');
  }
  else {
    fbq('track', '{{fBPixelType}}');
  }