I am working on Lightning Rollout Specialist super badge and when I check for first challenge, I am recieving error as "
You need to run the Lightning Experience Readiness Check for your org." 
I did run the readiness check and I received email as" Lightning Experience Readiness Report isn't available
It's not you, it's us. We can't evaluate your features and customizations right now.
Please try again later" I tried again after long time but still same thing.

Did anyone faced this issue as well and what might be the case of this issue?

Thank you