To complete the challenge in Trailhead your developer org should contain any namespace. You can check your developer org by following below steps Setup -->Create->Package Check whether your org contains any namespace. If it has also don't worry create new developer org and use that for complete the trailhead challenges
There is no way to remove namespace but you have created package with wrong namespace then following link helps u.. https://success.salesforce.com/ideaview?id=08730000000BqjiAAC
:::======================================================================::: Qusetion Solved ? then mark as best answer to make helpful to others .....
I was do that, still i can't complete my Trailhead challenge, it gives me following error now..
"There was an unhandled exception. Please reference ID: XDFYPHGE. Error: Faraday::Error::ResourceNotFound. Message: NOT_FOUND: The requested resource does not exist "
i know this is a very old post.!! may be useful for some other facing the issue. Try using "Manage my hands on org" from the challenge and then "connect an org" from the next page. This worked for me.
There is no way to remove namespace but you have created package with wrong namespace then following link helps u..
https://success.salesforce.com/ideaview?id=08730000000BqjiAAC
:::======================================================================:::
Qusetion Solved ? then mark as best answer to make helpful to others .....
still i can't complete my Trailhead challenge, it gives me following error now..
"There was an unhandled exception. Please reference ID: XDFYPHGE. Error: Faraday::Error::ResourceNotFound. Message: NOT_FOUND: The requested resource does not exist "
How can i complete my challenge???????
Thanx in Advanvce :)
Try using "Manage my hands on org" from the challenge and then "connect an org" from the next page. This worked for me.