I created a new developer org to fulfill the trailhead modules but at the beginning of of validating a challenge I get the error:
"No app named ......"was found".


Because of his error I started again in the old environment to reproduce the challenge and everything works fine.
Can someone helps me what is blocking in the new developer org? I tried again to registrate for a third develop org but it gives the same problem when I reproduce the challenge.
 

I created a new developer org to fulfill the trailhead modules but at the beginning of of validating a challenge I get the error:
"No app named ......"was found".


Because of his error I started again in the old environment to reproduce the challenge and everything works fine.
Can someone helps me what is blocking in the new developer org? I tried again to registrate for a third develop org but it gives the same problem when I reproduce the challenge.