SharePoint Online/External Sharing - AADSTS9007 Error while external sharing

KareemEckstein Dealing with the AADSTS9007 error during external sharing on SharePoint Online or Teams can be a bit of a puzzle, especially since it pops up sporadically. The workaround you've found points towards a glitch in handling permissions or authentication tokens. A good starting point would be to double-check your SharePoint and OneDrive external sharing configurations.

Occasionally, a slight misconfiguration here can lead to such access issues. It's also worth making sure the content shared has the appropriate permissions set up, ensuring nothing's amiss on that front. Peeking into Azure Active Directory's conditional access policies might shed some light too. There could be something in those policies that's not playing nice with external access attempts. Another quick fix could involve suggesting to those affected to clear their browser's cache or switch browsers. It's surprising how often these steps can resolve such issues. If these steps don't clear things up, reaching out to Microsoft Support could be your next move. They can offer insights specific to your setup and the problems you're encountering.

Also, reminding external users to pick the correct account type when accessing the shared content can prevent unnecessary hiccups. Keeping an eye on patterns or similarities among affected users can guide you towards a more consistent solution, cutting down on the need for individual workarounds.