Attempting to open a song file NWC's Viewer may fail with the message: "File uses new format."
This may mean that a current download of the Viewer is needed. The most up to date viewer can be found in the Public Address (https://forum.noteworthycomposer.com/?board=10.0) Forum. It may also mean that no Viewer (yet) exists for this version of the song file.
An alternative is to save the song as type: 'NWC Text File' (nwctxt). Often, the Viewer will be able to load the nwctxt file. Some files may not display properly.
A file with the extension: 'nwc' contains version information that usually increments with each change to its binary file format. The nwctxt file version is rarely updated. This allows the viewer to open nwctxt files using more relaxed standards.
Thanks for the useful tip.