Hi,
    I had to create a new playground for a different error. In the new playground i started getting a funny error. Now this is what I have observed:
The Error thrown is

Challenge not yet complete in Original Trailhead Playground
I could not find a button name 'Google_Info' on a Contact page layout.

When I try removing the Google Info Button from the Contact Page Layout, I can physically remove it but it still keeps showing the reference. I also tried deleting the Google_Info button but in vain. It keeps showing reference to the Contact Layout Page. I tried placing the button on the layout and also removing it, but no change in result.

Finally for completing the challenge I again get the same error:

Challenge not yet complete in Original Trailhead Playground
I could not find a button name 'Google_Info' on a Contact page layout.

Same Error in  Admin beginner -> Lightning Experience Customization -> Create Custom Links and Buttons

There was an unexpected error while verifying this challenge. Usually this is due to some pre-existing configuration or code in the challenge Org. We recommend using a new Developer Edition (DE) to check this challenge. If you're using a new DE and seeing this error, please post to the developer forums and reference error id: IFRINKLL

Hi,
    I had to create a new playground for a different error. In the new playground i started getting a funny error. Now this is what I have observed:
The Error thrown is

Challenge not yet complete in Original Trailhead Playground
I could not find a button name 'Google_Info' on a Contact page layout.

When I try removing the Google Info Button from the Contact Page Layout, I can physically remove it but it still keeps showing the reference. I also tried deleting the Google_Info button but in vain. It keeps showing reference to the Contact Layout Page. I tried placing the button on the layout and also removing it, but no change in result.

Finally for completing the challenge I again get the same error:

Challenge not yet complete in Original Trailhead Playground
I could not find a button name 'Google_Info' on a Contact page layout.

Same Error in  Admin beginner -> Lightning Experience Customization -> Create Custom Links and Buttons

There was an unexpected error while verifying this challenge. Usually this is due to some pre-existing configuration or code in the challenge Org. We recommend using a new Developer Edition (DE) to check this challenge. If you're using a new DE and seeing this error, please post to the developer forums and reference error id: IFRINKLL

I'm doing the simple lightning components challenge and have hit this problem in my existing trailhead org and a brand new dev org that I've just created:

Challenge not yet complete... here's what's wrong: 
There was an unexpected error while verifying this challenge. Usually this is due to some pre-existing configuration or code in the challenge Org. We recommend using a new Developer Edition (DE) to check this challenge. If you're using a new DE and seeing this error, please post to the developer forums and reference error id: QVWBQHAG