Challenge Not yet complete... here's what's wrong: 
Permission Set 'Temporary Account Edit' is not referenced in the flow 'Accounts Temp Access'. Check the instructions.



Create a flow that activates a session-based permission set
Before You Start
If you haven’t already done so, complete the challenges in the previous unit in this module before attempting this challenge. Otherwise, this challenge doesn't pass.
Challenge Requirements
You have a session-based permission set that you’d like to activate, but you don’t code. Create a flow that activates a permission set named Temporary Account Edit. Make sure Lynda Herman can run the flow by enabling the Manage Force.com Flow permission on the Read Only Clone profile.
In the Read Only Clone profile you created in the previous unit's challenge, enable the Manage Force.com Flow permission
Create a flow
Flow name: Accounts Temp Access
Make sure the flow references a session-based permission set named Temporary Account Edit as an input
Type: Flow
Activate the flow
 

I'm stuck on this trailhead. "Activate Session-Based Permission Sets Without Code"

I believe I did everything correctly.  I get "Challenge Not yet complete... here's what's wrong: 
Permission Set 'Temporary Account Edit' is not referenced in the flow 'Accounts Temp Access'. Check the instructions"

I can run the flow successfully, and I can confirm via setup audit trail that the permission set activation occured.