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 created.

Challenge not yet complete (https://trailhead.salesforce.com/fr/content/learn/projects/roll-out-lightning-experience-to-your-sales-team/customize-a-sales-console-app (https://trailhead.salesforce.com/fr/content/learn/projects/roll-out-lightning-experience-to-your-sales-team/customize-a-sales-console-app" style="color:blue; text-decoration:underline))... 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: QFEKNZCK

Thank you
 

Build a Conference Management App --> Create an Aura Component

I have tried to Copy/Paste using CTRL+C and CTRL+V, using the mouse copy/paste functions and also writing the code manually but all attempts fail. Are there any other ways of copying the text so I can complete this challenge ?

Hello! 
Please I would like how to choose my language in Thrailhead. http://developer.salesforce.com always open in french on my computer.
Thanks