This may be caused by some fonts that you use. You got to make sure that you have them installed on your computer before you save. To install any fonts, you can go to Start > Control Panel > Appearance and Personalization > Fonts, click on File and select Install new Font. Click Add Fonts and search for the location of the font. You can use Google in order to find any font that you like, but be sure that you download one only from trusted sources. You can also try using a default font like Times New Roman or Arial and save your project. If the error persist, it's caused by an internal error of the software and you need to contact the developer for additional support.
Because the program crashed while saving, the files that you see as the saved ones cannot be used. They are corrupt and there is no way to open them.