You can't sign in as a different user after you receive an access denied message on a SharePoint Online site
Not sure what release of Office 365 you're using? Go to the following Microsoft website:
When you try to access a resource while you are signed in to a Microsoft SharePoint Online site, you receive the following error message:
After you receive this error message, you don't have the option to sign in as a different user.
To work around this issue, follow these steps:
- Sign out of the organization for the current user account.
- Sign in again, and use the account that you want to use to access the resource.
In this scenario, the SharePoint Online account to which you are signed in doesn't have access to the resource.
You may encounter this issue if you've received the latest SharePoint Online service update.
Article ID: 2787034 - Last Review: 02/27/2013 04:23:00 - Revision: 5.0
Microsoft Office 365 for enterprises (pre-upgrade), Microsoft Office 365 for small businesses (pre-upgrade), Microsoft Office 365 for education (pre-upgrade), Microsoft SharePoint Online
- o365 o365a o365e o365p o365m o365062011 pre-upgrade KB2787034