I have seen this behaviour sometimes when the user does not log out properly but it’s hard to say without any specifics. You may want to recheck the access permissions to the page/menus and whether the course is correctly assigned to catalogue(s) they have access to...Note that once a user is enrolled, they can bypass what would normally needed to access the course so depending from where they are trying to access the course, it could display a 403 error.

@becky.detrempe It might be worth opening a ticket especially if you can recreate the behavior. Is it happening to all the users enrolled? Also, do you know if they’re having to authenticate with your IDP after they click the link or whether they’re already logged in. That might be information that could help support investigate should you open a ticket. 

its not happening to everyone, and its just sometimes so not sure it could be recreated as it is not every time.  it seems like if they wait and retry it will eventually work.  Wasnt sure if maybe it happens because too many trying to access at the same time or if there was a delay and timing out?  I really am not sure but is has happened a few times with different users

Do you have Extended Enterprise? If so make sure you’re using the branch corresponding to the person you’re sending the link to. I’ll forget to do this sometimes & then half the people i send the link to can’t access it...Additionally, I feel like Docebo might have changed the way they make enrollment links in the last couple of months, we had to regenerate a few of them.

I would start a log of users and courses when this happens since it’s not universal. It may seem random but there is probably some underlying commonality.

Had they just been enrolled when they tried the first time and got the 403? Could be a simple cache issue at that point?