I am in the midst of completing the Agentblazer Champion trailhead and have completed 83% of it. I am however stuck at the project quick start portion.

Hi everyone,  

I am in the midst of completing the Agentblazer Champion trailhead and have completed 83% of it. I am however stuck at the project quick start portion - which is under the Agentforce Builder section. 

 I have followed and completed all the required steps, however, when I am unable to test the conversation preview as I keep getting an error message. This occurs even after I refresh the page.  

Has any one else faced the same issue? 

Looking forward to some assistance on this, thanks in advance!