Recover Navisworks Files
Power cuts and system and software failures can cause Navisworks to close before you can save changes to your file.
Navisworks can automatically save backup versions of a file you are working on, enabling you to recover your work if Navisworks closes abnormally.
Auto-saved files have an .nwf extension, and are named as {FileName}.AutoSave{x} where {FileName} is the name of the current Navisworks file, and {x} is a number that increments with each auto-save. So, for example, if you work with a file called Enviro-Dome.nwd, the first auto-saved file is called Enviro-Dome.Autosave0.nwf, the second auto-saved file is called Enviro-Dome.Autosave1.nwf and so on.