Hello @KathyKyle 

Sorry that you have been running into this issue! 

-Off hand, it sounds like the email addresses for the students you are adding have not been confirmed by the user or something.

• Are they able to log into their Canvas account with the email address you are using to add them? If so, have them click on the Account button, select Settings and verify that the email address they have set as the default isn't displaying an Exclamation icon. This can sometimes indicate that they need to confirm the email address, which might explain why they are not seeing anything when the invite is sent out to them. 
• Do they receive a PW reset email when they try and reset their passwords?  

-Colton