Yeah
I reckon your error message means "cannot open as a valid WP format file".
Something is clearly broken, but you may be able to recover lots by opening with a text editor.
I haven't used WP myself since the days of 5 1/4" floppies (when a floppy really WAS floppy!). I recall it was a better product than MS Word at the time, but I got corporatised...
