Thank you for your post!
I understand that you're having issues with Azure AD B2B where you invited an external user and when the user is trying to accept the invitation, you're running into an unexpected, attached file issue. To hopefully help point you in the right direction or resolve your issue, I'll share my findings below.
When it comes to your attached file issue during the invitation redemption process, I wasn't able to find anything specific on this, but the external user should also be able to redeem your invitation by:
- Selecting the
- Or copying the URL and pasting it into a private browsing session rather than clicking on the URL from the email.
Depending on the error message that you're receiving, you can also reference the Troubleshooting Azure Active Directory B2B collaboration documentation for more details:
- The user that I invited is receiving an error during the redemption process
- Invitee’s Admin has disallowed EmailVerified Users from being created in their tenant
- External user doesn't exist already in a federated domain
- External user has a proxyAddress that conflicts with a proxyAddress of an existing local user
I hope this helps!
If you're still having issues, can you share a screenshot of the error message that you're running into so I can gain a better understanding of your issue.
Thank you for your time and patience throughout this issue.
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