Hello Experts 

I tried to verify one of the trailhead " Battle station" 
and i got this error 
please can you help ? 

Thank you 
Step 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: OZXVVKJM 
Remarque : Si vous avez ignoré les étapes précédentes, vous risquez de rencontrer des erreurs.