If you wanted to make sure your blog or website URL will look neat when shared on Facebook or Twitter, then you might already use the Facebook Debugger Tool. And I can also say that you already encountered the error message below while using it.

Invalid App ID
The specified 'fb:app:id' property is not a valid app ID.

Even though I am not that pro when it comes to using the Facebook debugger, I can say that this error message is simply all about your App ID wherein it is missing in your Blogger's theme HTML meta code. For this tutorial, we are going to solve this error that occurs while debugging our Blogger website or blog using the tool. You do not have to worry because the steps are just too easy and you can do this in a flash.

For this tutorial, you will be needing the following:

a. Facebook App ID.

b. Privacy Policy page of your blog or website.

STEPS:

1. Open your Facebook account and go to Facebook Developers Apps page, click here.

2. Now, click the "Add a new app" button.

3. In "Create a New App ID" type your desired Display Name as well as the Contact Email. And press "Create App ID".

4. For the "Security Check", just check the box and click the Submit button.


5. Now, press the OFF button.


6. After pressing the OFF button, a page will appear, just click the "Basic Settings".

7. In the Privacy Policy URL, enter the URL of your blog/website Privacy Policy Page. Then save your work.


8. Again, try to press the OFF button, if the image below appears, then you only have to choose in what Category your website belongs, and then press the Confirm button.

9. Upon clicking the OFF button, it will now be turned ON.


10. When your button is already ON and colored light green, then your App is now Live.



11. Copy the App ID.



12. Go to your Blogger Theme > Edit HTML.

13. Search and find (Ctrl + F) the word fb:app_id. When you find it, the whole code will be the same as the code below.

<meta property="fb:app_id" content="FB App ID"/>

14. Replace the "FB App ID" with your own ID. Save your template. Rerun the Facebook debugger and see if the "The specified 'fb:app:id' property is not a valid app ID" is still there or gone already.

 15. Done!

 If you have a question or something to share regarding this tutorial, you may leave a comment below. Thanks!