User should be able add Case Comment and edit the case Comment when the model is on the case object

I am unable to edit the case comment and render CreatedBy ( on case comment Object) . 

Can anyone please help me?

 Though I went with an approach of rendering a table ( on Case Comment Object) on button click.
But in this approach again now I am not able to render the case comments of a particular caseID ( ParentId).

Hi Sreekar, thanks for the screenshots.   The first thing I’d check would be permissions to verify that you are able to view and edit these fields:

  • If you have admin privileges, double check that your profile has permission to edit the Case Comment field in permission sets and in the Case object on the Case Comment field itself.
  • In the same way, check that you have view permissions on the Created By field.
If needed, here's more information about field-level security in Salesforce along with instructions on how to do the above: https://help.salesforce.com/articleView?id=admin_fls.htm&type=5