Your Facebook has been working well for months, even years, when all of a sudden you log in and all you get is a blank white page. No data. What happened?
This is clearly a Facebook issue that is brought on by their system cleaning up the databases. That is the way the FB team keeps their servers running. There are several methods to resolve the issue, however, one way to prevent the problem of recovery is to make a backup of your FB page. That way you can reinstate the page when necessary.
To do so, log in to your Facebook page. Click the small arrow to the right of the world icon, (upper menu). Click on Settings. Click Download a copy… Then click Start My Archive. Enter your FB password and follow the prompts where you will get two emails indicating a backup is being made and one that states a backup has been completed. Click the link on the second email that will allow you to download a copy of your FB page. Save it to a folder on your backup drive / folder. Done.