
Hello Gry,
Thank you for reaching out to Microsoft Community!
SharePoint is built for business use and needs a Microsoft 365 business subscription. Personal accounts usually can't access SharePoint unless they’re invited by a company. If access stops working, it’s likely because the invitation expired or the organization removed permissions.
Therefore, in this case, you need to ask the organization re-invites your account to retrieve for the document. This is the preference article for your SharePoint owner: Set up and manage access requests - Microsoft Support
Hope this information will be helpful for you. Please reach out me again if you still have any questions or concerns.
Best Regards,
Alina-Le - MSFT | Microsoft Community Support Specialist