iTunes Connect - Can't invite "internal testers" for prerelease app

Question

I got my app approved for distribution through the new Apple TestFlight app. I tried to invite an "internal tester" through iTunes Connect ->Prerelease ->Internal Testers but all I see are 2 info boxes:

1. To start testing, select at least one Internal Tester.

2. Internal testers can be added in Users and Roles. Internal testers are iTunes Connect users with the Admin or Technical role.

I already added an Admin an Technical user to Users and Roles but I can't invite them. How to invite an internal tester?

Answer 1

Problem solved: The email for an internal tester was also used for an external tester. As soon as I removed the email from the external testers list I could invite the user as an internal tester.

Answer 2

To add people to internal testers you need to go

1. "Users and Roles"
2. List item
3. Select the user Switch on Internal Tester
4. Save