Dear Dellen Steve Gorit,
Good day! Thank you for posting in our community. It seems you are encountering issue accessing any shared resources or files after account reactivation. This happens normally because new profile is created with account activation. However, in the shared sites and his own OneDrive, it cached his old profile. Therefore, permission was mistakenly granted to the cached profile instead of new one. To resolve the problem, please follow below steps.
For his own OneDrive:
1, Remove him from OneDrive admin
Go to M365 admin center and sign in to SharePoint admin account, click "SharePoint admin center" on left side >> In SharePoint admin center, click more features >> User profiles >> Manage user profiles >> Find the user account who has the problem >> right click it >> Manage site collection owners >> Remove him from both "site collection admin" and "primary site collection admin", add SharePoint admin account to these 2 locations.
2, Remove user from OneDrive site user list
- Go to M365 admin center, search for the user fromActive users page >> click his display name >> in the right side pane, click OneDrive >> create link to this user files >> copy the link.
- Paste the link to notepad, add /_Layouts/15/people.aspx?MembershipGroupID=0 at end of the URL. For example, the user onedrive URL is https://domain-my.sharepoint.com/personal/userA_domain_com, the modified URL should be https://domain-my.sharepoint.com/personal/userA_domain_com/_Layouts/15/people.aspx?MembershipGroupID=0
- Open the modified URL. In this page, find the user account >> Actions >> delete user from this site collection.
3, Re-add user as OneDrive admin
- Go back to "manage user profiles" page follow step 1 and re-add the user to "Primary site collection admin" and "site collection admin".
For SharePoint shared files:
- Go to the related SharePoint site, add /_Layouts/15/people.aspx?MembershipGroupID=0 at end of the site URL. For example, the SharePoint site URL is https://domain.sharepoint.com/sites/siteA, the modified URL should be https://domain.sharepoint.com/sites/siteA/_Layouts/15/people.aspx?MembershipGroupID=0
- Open the modified URL. In this page, find the user account >> Actions >> delete user from this site collection.
- Then find the file/folder that tried to share with the user, re-share it by clicking "share" button >> link type choose "specific people" >> enter user A account >> send/copy link.
Thank you for your cooperation and have a nice day!
Best Regards,