Fix for the Domain is null and Invalid or missing value for property.

 Recently, I have updated my local instance and while doing the new registration or login got the below error

The Domain is null and is probably not defined in Domain Manager

When I checked my domain configuration under site settings

/sitecore/content/Tenant/Sitecore/Settings/Site Grouping/Site

I found the reference of the domain didn't exist on my local system, I created a new domain through the admin panel here

After fixing that, during the registration, I got a diff error

 {  
  "IsSignupFlow": false,  
  "UserName": null,  
  "Errors": [  
   "An unknown error occurred. Please verify your entry and try again. If the problem persists, please contact your system administrator."  
  ],  
  "HasErrors": true,  
  "HasInfo": false,  
  "HasWarnings": false,  
  "Info": [  
  ],  
  "Success": false,  
  "Url": null,  
  "Warnings": [  
  ],  
  "ContentEncoding": null,  
  "ContentType": null,  
  "Data": null,  
  "JsonRequestBehavior": 1,  
  "MaxJsonLength": null,  
  "RecursionLimit": null  
 }  

I opened my session in a new incognito window and found below errors -

 {  
  "IsSignupFlow": false,  
  "UserName": null,  
  "Errors": [  
   "Invalid or missing value for property \u0027Domain\u0027."  
  ],  
  "HasErrors": true,  
  "HasInfo": false,  
  "HasWarnings": false,  
  "Info": [  
  ],  
  "Success": false,  
  "Url": null,  
  "Warnings": [  
  ],  
  "ContentEncoding": null,  
  "ContentType": null,  
  "Data": null,  
  "JsonRequestBehavior": 1,  
  "MaxJsonLength": null,  
  "RecursionLimit": null  
 }  

I updated the existing domain in site groping,  to see if it's working because, because I haven't added this domain in the commerce configuration .

 {  
  "IsSignupFlow": false,  
  "UserName": null,  
  "Errors": [  
   "Customer \u0027Storefront\\jitusonijk@gmail.com\u0027 already exists."  
  ],  
  "HasErrors": true,  
  "HasInfo": false,  
  "HasWarnings": false,  
  "Info": [  
  ],  
  "Success": false,  
  "Url": null,  
  "Warnings": [  
  ],  
  "ContentEncoding": null,  
  "ContentType": null,  
  "Data": null,  
  "JsonRequestBehavior": 1,  
  "MaxJsonLength": null,  
  "RecursionLimit": null  
 }  

So abve message is because I had the same user already registered, I did a new registration and it worked for me.

The issue/learning was - If you create a new domain configuration please make sure that we need to update the site groping and policies accordingly.

PlugIn.AdventureWorks.CommerceAuthoring-1.0.0.json

PlugIn.Habitat.CommerceAuthoring-1.0.0.json

PlugIn.YourSite.CommerceAuthoring-1.0.0.json