"font family not available" error (15875)

Hi JohnR-

Sorry, over a year later, I finally checked back on this thread and saw your request. I did indeed come up with a workable solution after some more tinkering, which I've posted below. It's pretty specific to the fairly controlled environment I'm working in - if you ran this on a document with a different set of paragraph styles from what we're using, you'd get errors - but the methodology should be applicable to other environments with some modifications. Hope it's useful to others.

var FindAppliedParagraphStyle=new Array()
var FindAppliedFont=new Array()
var FindAppliedFontStyle=new Array()
var ReplaceFontStyle=new Array()

//change all instances of Symbol font to Regular
app.findTextPreferences.appliedFont="Symbol"
app.changeTextPreferences.fontStyle="Regular"
app.changeText()
app.findTextPreferences = null;     app.changeTextPreferences = null;

//define styles to be replaced. 
FindAppliedParagraphStyle[0]="Abstract"; FindAppliedFont[0]="Helvetica Neue LT Std"; FindAppliedFontStyle[0]="Bold Italic"; ReplaceFontStyle[0]="66 Medium Italic";
FindAppliedParagraphStyle[1]="Abstract"; FindAppliedFont[1]="Helvetica Neue LT Std"; FindAppliedFontStyle[1]="Bold"; ReplaceFontStyle[1]="65 Medium";
FindAppliedParagraphStyle[2]="Abstract"; FindAppliedFont[2]="Helvetica Neue LT Std"; FindAppliedFontStyle[2]="Regular"; ReplaceFontStyle[2]="65 Medium";
FindAppliedParagraphStyle[3]="Para_Text"; FindAppliedFont[3]="Helvetica Neue LT Std"; FindAppliedFontStyle[3]="Italic"; ReplaceFontStyle[3]="56 Italic";
FindAppliedParagraphStyle[4]="Para_Text"; FindAppliedFont[4]="Helvetica Neue LT Std"; FindAppliedFontStyle[4]="Regular"; ReplaceFontStyle[4]="55 Roman";
FindAppliedParagraphStyle[5]="Flush_Left"; FindAppliedFont[5]="Helvetica Neue LT Std"; FindAppliedFontStyle[5]="Italic"; ReplaceFontStyle[5]="56 Italic";
FindAppliedParagraphStyle[6]="Flush_Left"; FindAppliedFont[6]="Helvetica Neue LT Std"; FindAppliedFontStyle[6]="Regular"; ReplaceFontStyle[6]="55 Roman";
FindAppliedParagraphStyle[7]="Bib_Reference"; FindAppliedFont[7]="Helvetica Neue LT Std"; FindAppliedFontStyle[7]="Italic"; ReplaceFontStyle[7]="56 Italic";
FindAppliedParagraphStyle[8]="Bib_Reference"; FindAppliedFont[8]="Helvetica Neue LT Std"; FindAppliedFontStyle[8]="Regular"; ReplaceFontStyle[8]="55 Roman";
FindAppliedParagraphStyle[9]="Figure_Leg_Cont"; FindAppliedFont[9]="Helvetica Neue LT Std"; FindAppliedFontStyle[9]="Italic"; ReplaceFontStyle[9]="56 Italic";
FindAppliedParagraphStyle[10]="Figure_Leg_Cont"; FindAppliedFont[10]="Helvetica Neue LT Std"; FindAppliedFontStyle[10]="Regular"; ReplaceFontStyle[10]="55 Roman";
FindAppliedParagraphStyle[11]="Figure_Legend"; FindAppliedFont[11]="Helvetica Neue LT Std"; FindAppliedFontStyle[11]="Italic"; ReplaceFontStyle[11]="76 Bold Italic";
FindAppliedParagraphStyle[12]="Figure_Legend"; FindAppliedFont[12]="Helvetica Neue LT Std"; FindAppliedFontStyle[12]="Regular"; ReplaceFontStyle[12]="75 Bold";
FindAppliedParagraphStyle[13]="TableLegend"; FindAppliedFont[13]="Helvetica Neue LT Std"; FindAppliedFontStyle[13]="Italic"; ReplaceFontStyle[13]="56 Italic";
FindAppliedParagraphStyle[14]="TableLegend"; FindAppliedFont[14]="Helvetica Neue LT Std"; FindAppliedFontStyle[14]="Regular"; ReplaceFontStyle[14]="55 Roman";
FindAppliedParagraphStyle[15]="Table_Body"; FindAppliedFont[15]="Helvetica Neue LT Std"; FindAppliedFontStyle[15]="Italic"; ReplaceFontStyle[15]="56 Italic";
FindAppliedParagraphStyle[16]="Table_Body"; FindAppliedFont[16]="Helvetica Neue LT Std"; FindAppliedFontStyle[16]="Regular"; ReplaceFontStyle[16]="55 Roman";


//NOTE: new entries can be added by simply adding a new line at the end that follows the pattern laid out above

//loop through all the find/replaces above
for (i = 0; i < FindAppliedParagraphStyle.length; i++) {

     //test to see if there are missing fonts. 
     try {fontLocs = app.activeDocument.fonts.everyItem().location; 
     //if not, break.
     app.findTextPreferences = null;     app.changeTextPreferences = null; alert("All missing fonts have been corrected."); break} 
     //if so, try to correct by running find/replaces with the criteria above.     
     catch (err) {
          
          //clear find/change preferences
          app.findTextPreferences = null;     app.changeTextPreferences = null;

          //find and replace missing fonts based on the search criteria in the array
          //app.findPreferences.appliedParagraphStyle=FindAppliedParagraphStyle
          app.findTextPreferences.appliedParagraphStyle=FindAppliedParagraphStyle
          app.findTextPreferences.appliedFont=FindAppliedFont+"     "+FindAppliedFontStyle
          app.changeTextPreferences.fontStyle=ReplaceFontStyle
          app.changeText();
     
     }

}
//if all searches have been run and there are still missing fonts, alert the user
if (i==FindAppliedParagraphStyle.length) 
{
app.findTextPreferences = null;     app.changeTextPreferences = null; 
alert("There are still missing fonts. Go to Type > Find Font to find them.");
}

Thanks! I think we need to append the fontstyle, only when it is not falling on the default categories like Regular, Italic, Bold, BoldItalic.