Hello !
I developed my application using zat server, and successfully validated my bundle using zat validate. I could navigate to my app using the ?zat=true parameter during the development process.
Now when I uploaded my application through the admin settings, I get an HTTP error 422: 
Would you be able to know why it fails like so ? What am I doing wrong ?
Suite à l'appel de Blandine, j'essaye de trouver la personne chez nous qui pourrait t'aider à cette étape.
Don't hesitate to add any additonal info here in english so my colleague can pick it up and help you .
Cheers
Alex