Hi @Christopher Goble ,
Does one user or all users have this issue?
Can this problem be reproduced on other computers?
According to the error message, it seems that the users aren't yet assigned a license. To check it, please sign in to the Microsoft 365 portal (https://portal.office.com) as an admin.
- Click users and groups, and then click active users.
- Click Filter and then in the drop-down box, click Unlicensed users.
NoteTo assign a license to a user, double-click the user. On the "Assign licenses" page, click to select the check boxes next to the items that you want to assign, and then click save.
If user has owned the license, please try to sign into the account in another browser to see how it goes.
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