Each night the system checks all of your layers and makes a backup of any layers that have changed since the last time the layer was backed up. Each backup is saved seperately rather than overwriting the previous backup. The result is that we have a backup of each of your layers from every day that you made changes.
How to recover an older version of a layer
1. Click Layers then click the layer name that you want to recover
2. Click the 'More' tab and then click 'Backup Manager'
3. Select one of the backup files from this list. The files are named according to the date and time that the backup was created. Note that most backups happen in the early morning hours and are stamped with Eastern Standard Time.
4. Click the 'Restore' button.
5. It is important to note that backup will be restored to a new layer and will NOT overwrite your currently layer. This allows you to compare the two layers before deciding if you want to keep it. If you want to keep the restored layer then you can delete the original layer and rename the restored layer to that of the original.
How to force a backup now
If you are getting ready to do something experimental to a layer and want to be sure you can reset back to this point if something goes wrong, then click the 'Create Backup' button. This will perform a backup of the layer immediately and add it to your list of backups.
How to restore a deleted layer
The above recovery process only works if the layer is still a part of your map. If you want to restore a layer that has been deleted then click the "recover deleted layer" link at the bottom of the Backup Manager form. This will give you a list of all layers that were recently deleted from this map.