Are you able to user any other users to run this functionality? If so I suggest checking the roles that have been provided for that user.
As the per the previous reply check the access granted to the role PegaRules:user4 you can this by going to Security->Access Role Name and looking for the user4 role when you open up the instance you will see all the access granted to this role. (see the attached image)
You need to look for the rules that are denied access as per your mail.