How can I retake a challenge in Trailhead?  I thought I was able to this before.  I am in one of my Trailhead playgrounds.

Thanks,
Steve

I have installed APP Exchange packages in production and QC.  How do I get it to allow me to install a package in my Trailhead Playground?  The only choices AppExchange gives me are production or Sandbox.

Thanks,
Steve

Hello,

Through the Propack Training to get certified, I am beginning the Salesforce Platform Basics module.  

First of all, it says it's only for Lightning, though my company doesn't use it.  So will going into my Trailhead Playground suddenly put me in Lightning, or do I need go elsewhere to complete the same training and challenge in Salesforce Classic?

Second, when I hit the Launch button to go into my Trailhead Playground, it seems to take me to a general area of Trailhead, not to this specific module.  Is this because I'm not in Lightning?

Thanks,
Steve  
 

I am setting up a workflow rule that will trigger an email alert when a specific user gets cases assigned to her.  I'm able to choose her name in the Recipients section of the Email Alert.  But when I try to save it, I get these messages -

Top of screen - Error: Invalid Data. 
Review all error messages below to correct your data.
The page you submitted was invalid for your session. Please click Save again to confirm your change.

Under the recipient type field - 
Your search returned more than 100 rows. Only the first 100 are displayed. Please refine search criteria.

But the user's name is clearly chosen in the Selected Recipients field.

Thanks,
Steve