Eric salamat (thanks)

I did what you suggested. Until the matter of going to System Preferences. 
The Preferences  in my System folder doesn’t have the Nisus Writer Fonts
List. 
Instead I have: 
Nisus Compact Preferences, Nisus Equation Tool Settings, Nisus Font Menu
Cache. Nisus Table Tool Preferences, Nisus Writer 6.0 Preferenc copy,
Nisus Writer 6.0 Word Services.

I accessed my work and got this message "Cannot read text...out of memory"