TItle Page Publisher or FORMAT > Element Styles crashes / hangs with a blank window (MacOS only)

Are you having a problem on Mac Screenwriter 6.7 with opening the Title Page Publisher and/or FORMAT > Element Styles, where they crash or hang and only display a blank / empty window?

This is a sign that you have a corrupted or duplicate font.  It is easy to fix:

1. Open Apple's Font Book program (it's in the Applications folder).  
   
   
2. Select All Fonts on the left side.
   
   
3. Click on any font in the All Fonts list (second column)
   
   
4. Press COMMAND+A to select all the fonts
   
   
5. Under the File Menu, select "Validate Fonts"
   
   
6. You probably see some fonts listed as having problems.  If you've been a Mac user for a long time, and moved from machine to machine, then this isn't unusual.  However, you should start by removing any duplicate fonts.  The summary of problems window will let you select a checkbox for any fonts you need to remove, then there's a button to press to "Remove Fonts".
   
   
7. You can start by removing any duplicates, and any fonts where there aren't minor issues.  
   
   
8. Then, go back to Screenwriter and try bringing up the Format > Element Styles or the Title Page Publisher again.