Adding students to my class, it keeps telling me that I have to add the students to my class and I already did it

See this document:

https://khanacademy.zendesk.com/hc/en-us/articles/204577244-Add-students-to-an-existing-class

I am having the same problem. 

I have a class and code. I have added students to my coaching site, but for some reason I cannot add them to the class I created.

Class was created student accounts were created and they are not in my class. How do I do that?

Hello all! My name is Lisa Krueger and I am a Khan Academy Ambassador teaching in Chicago. I am sorry you have having an issue with class rosters. So a few things to check first:

1. Students are in your Roster - many students forget to click the Accept button next to coach's name.
2. Students are logged into the account you have in your Roster - had many students who forgot passwords or accounts so they created a new one and that was why I wasn't able to see them.
3. From your Roster page click the box next to each student not assigned to a class then click Actions and choose Add to class (see image below)

Please let me know if any of this resolves the issue or not or if you have additional questions, comments, or suggestions. Thank you for posting.