Error message at file save
If you are not able to save a .nwc or a .bak file, the problem is most likely one of the following:
The file, or disk where the file resides, is read-only (solution: use a different drive, or unmark the read-only attribute for the file or files).
The disk is full (solution: clear disk space).
The disk is malfunctioning (solution: try a different drive).
The computer has some other problem that is just manifesting itself when using NWC save on this file or files (perform computer diagnostics/virus checking/try a different drive).
Also, make sure you have not used a character not supported in file names. File names cannot contain the following characters:
/ : * ? " < > |