I keep receiving the following error message when attempting to clear:

"Challenge Not yet complete... here's what's wrong:  Could not find notification on dashboard. Please check the requirements again." 
(Task - Create a notification to alert you when lost opportunities exceed a certain amount)

The alert is created and set to run. When you Save and Run the alert, it disables it for some reason and you can't see it as a widget in  the Notification Tracking section. When you Save only, it stays active and displays the widget on the Wave Analytics home page. It doesn't display on the Oppty Details dashboard though.

Any thoughts? I'd like to complete this trail and progress to the next part of the project.

Completed the challenge.  Added the notification (see attached image) in the Wave developer org.  It looks like it did not save the first time.  Added the notification a 2nd time, as shown in screen capture. 

In the Analyze Your Data Over Time module  where it says:

In the default exploration state, as you remember from the previous unit, the query is aggregating on count of rows with no grouping and no filtering. Start a new exploration by going back to the My DTC Sales app and opening the DTC Opportunity dataset. You’re interested in the number of tablets involved, so complete the following steps.
Click Count of Rows to change the measure.
Select Sum in the aggregation functions list.
Select # (number sign) for the measure to see the number of products in your closed opportunities

If I select Sum the only option is amout. Is the trailhead dataset in sync with the directions?

I keep receiving the following error message when attempting to clear:

"Challenge Not yet complete... here's what's wrong:  Could not find notification on dashboard. Please check the requirements again." 
(Task - Create a notification to alert you when lost opportunities exceed a certain amount)

The alert is created and set to run. When you Save and Run the alert, it disables it for some reason and you can't see it as a widget in  the Notification Tracking section. When you Save only, it stays active and displays the widget on the Wave Analytics home page. It doesn't display on the Oppty Details dashboard though.

Any thoughts? I'd like to complete this trail and progress to the next part of the project.

Completed the challenge.  Added the notification (see attached image) in the Wave developer org.  It looks like it did not save the first time.  Added the notification a 2nd time, as shown in screen capture.