Very frustrating. I've attempted this challenge in the DE I was previously working in where I created the reports that need to be added into the dashboard. I have now tried it in two separate NEW DEs where I recreated the reports and built the dashboard. The error code has changed from yesterday but the end result is the same:
Challenge Not yet complete... here's what's wrong:
There was an unexpected error while verifying this challenge. Usually this is due to some pre-existing configuration or code in the challenge Org. We recommend using a new Developer Edition (DE) to check this challenge. If you're using a new DE and seeing this error, please post to the developer forums and reference error id: HAKDYYXE
Any suggestions on how to move forward. The Dev Community account is new. However, this would be my 129th Trailhead badge.

How can I review the challenge questions after a challenge has been taken?

I am trying to use Data Loader to insert several Contact records for existing Accounts.  I have the Salesforce ID of the existing account but the error I get back is:  Organization Name: id value of incorrect type:001A000000yL5CnlAK/d.  That is the correct SF ID for the account (I have verified this)  Help!

I believe I completed the Define Sharing Rules challenge.  When I press the Check Challenge button, the following error is displayed:

Challenge Not yet complete... here's what's wrong: 
An object with the API name Project__c does not exist or does not contain the Priority__c picklist field.

I did create the Project object.  When view the Project object it indicates that the API Name is Project_c.  It has a custom field called Priority and the API Name is Priority_c.

What is going on with this challenge?

Hello...I have completed the 500 pts Challenge for Using the Report Builder in Reports & Dashboard Module, but I have not received my points.  I am signed into Developer Edition, what do I need to do for the system to acknowledge the completion of my challenge.
 

Unable go get Report to show.   Unsure of what is wrong - I can see it and open it in my Unfiled Public Reports.   When I try to rename it, it indicates it already exists.....I cannot move forward with next sessions......out of ideas of how to fix

I am getting this error below for the above challenge:
Challenge Not yet complete... here's what's wrong:
There was an unexpected error while verifying this challenge. Usually this is due to some pre-existing configuration or code in the challenge Org. We recommend using a new Developer Edition (DE) to check this challenge. If you're using a new DE and seeing this error, please post to the developer forums and reference error id: NIQZDKLE
I have a new org so not sure why I am getting this error

I am getting the following error:

The 'Sales Manager' dashboard does not have the correct headers and titles for the chart components.

Here is the screenshot of my dashboard