We’ve added some additional information about data recovery to the next edition of the manual, as it can be confusing:
In the unfortunate event that a backup is needed to fix a problem with your current working project, restoring couldn’t be easier. As noted previously, backups are by default just Zip archived projects, a compression format that is natively supported by all modern operating systems. They are, compression aside, no different from the project you work with on a daily basis, though they will be successivly older revisions, and therein lies their power. The only other thing that makes them special is that they are tucked away in a safe place and compressed, to help avoid being inadvertantly modified. If you are unsure of where your backups are located, you can always open the folder they are stored in by opening the Backup tab in [MAC:Scrivener/Preferences...
][WIN:Tools/Options...
] and clicking the button at the bottom, Open backup folder...
, to reveal them.
Once there, you’ll find a number of files named respectively with the projects they relate to. After the project name there will be a sequence number or a date stamp. It is best practice to select the backups you wish to check and copy them to a temporary location, first. The backup folder rotates content, so copying a set out will ensure these backups do not get deleted by Scrivener’s cleaning routine while you experiment. To do so, simply click and drag the selected .zip files while holding down the [MAC:Option][WIN:Ctrl] key, and drop them some place convenient, like your Desktop.
Locate the most recent backup[1] and unzip it by double-clicking on the ‘.zip’ file[ WIN: and dragging the “project name.scriv” folder that you see to the Desktop]. Zipped projects cannot be opened directly in Scrivener. The unzipped [MAC:project][WIN:folder] is a full project and can be opened in Scrivener in the usual way. Examine it, and if it will suffice, close it, then remove the broken version of the project and replace it with this extracted copy. You can now clean up the temporary working area if you wish and continue working as normal. If it contains the error as well, then proceed to the next older backup, continuing until you find a valid copy.
If you find you need to only restore pieces of a project, you can open your current working version at the same time as the backup, and drag those pieces from the restored backup project into the live working project, from binder to binder. This can be useful if you’ve done a lot of work since the last backup, and have only just noticed that one file had been accidentally messed up some time ago, and there are no snapshots to recover from.
Once you’ve finished, the files you’ve worked with on the Desktop can be removed at your convenience.

[1] The sequence number cannot be used to determine this as Scrivener rotates through numbers. If you have not enabled the date stamp option, you will need to use your operating system to determine the modification date of the file.
Hope this helps,
Katherine