Update: 6/6/2017: Please check https://support.office.com for the latest official information.
It's possible to restore a site to a previous point in time, but before proceeding with this action you have to ensure that there are no other solutions:
- User Recycle Bin
- Admin Recycle Bin
The time of the restore should be chosen based on the last known time in which the item(s) was in the desired state and no more than 14 days in the past.
SharePoint Online Support can restore a site collection/ sub site if there is no other way to resolve a possible problem and if it has a strong business impact.
The process of restoring a site involves multiple teams, so it can take some time, therefore, in case any issue appears, please report it as soon as possible.
It's important to explain the reason for the request in order to provide alternate solutions
What is the URL of the site collection that contains the item(s) needing to be restored?
What is the URL to the item(s) needing to be restored? If this is unknown, please specify as close as possible.
What is the reason for the restore request (eg. missing item, unwanted changes, etc…)?
When was the item(s) last known to be in the desired state?
Scenario: Corrupt Item
A list item or file has became corrupt.
- Check for working version via the file history
Scenario: Deleted Sub Web
A sub web was deleted and is no longer accessible.
- Check the Recycle Bin
Scenario: Site upgrade changed the look of the site
This is not a valid scenario for a restore. A site upgrade updates the behavior and chrome of a site, it does not manipulate the customers data within the site collection. If the site isn't functioning after a site upgrade we need to help them remove/correct their customizations.
Contact Microsoft Support immediatly to prevent any data loss.
Scenario's in which a restore is required:
A column on a list was removed (and the column contained data). Deleting a column from a list does not currently make use of the recycle bin. Instead, this data is immediately deleted and only recoverable via a point in time restore..