If a backup stops with an error before it finishes, the backup file it leaves behind may be incomplete. Part of your data may be missing from it.
Don't treat that file as a full copy of your site, and don't delete anything from your site because you have it.
Run the backup again. If it stops with an error a second time, contact support and tell us the error you saw.
In FW Real Estate, open Data Management to create a backup of your property data. Backups you make there are saved in wp-content/uploads/fwre/backups/.
To keep a copy of everything FW Real Estate holds on your site, back up wp-content/uploads/fwre/ together with the database. That pair is your real estate content; the plugin folder itself can be replaced.