Exception has been thrown by the target of an invocation. Error 1220: Illegal Argument

[AndrewBancroft00]

While running a JavaScript file from C#/COM, I will occasionally receive the error "Exception has been thrown by the target of an invocation. Error 1220: Illegal Argument", the error goes on to show the line # of the offending javascript, but this doesn't happen every time, and usually within a few retries it will pass.

What might cause this? Here is the javascript in question, and usually the error reports that line #8 is the offender "if (frames[x].textRange.characterAttributes.textFont != null) {"

var frames = app.activeDocument.textFrames;
var len = frames.length;

for (var x = 0; x < len; x++) {
    if (frames[x] != null) {
        if (frames[x].textRange != null) {
            if (frames[x].textRange.characterAttributes != null) {
                if (frames[x].textRange.characterAttributes.textFont != null) {
                    if (frames[x].textRange.characterAttributes.textFont.name != null) {
                        if (frames[x].textRange.characterAttributes.textFont.name.toLowerCase().indexOf("avenir") >= 0) {
                            if (frames[x].textRange.characterAttributes.textFont.name == "Avenir-BlackOblique") {
                                frames[x].textRange.characterAttributes.textFont = textFonts.getByName("ProximaNova-Bold");
                            } else if (frames[x].textRange.characterAttributes.textFont.name == "Avenir-Medium") {
                                frames[x].textRange.characterAttributes.textFont = textFonts.getByName("ProximaNova-Medium");
                            }
                        }
                    }
                }
            }
        }
    }
}

var avenirFonts = "";

for (var x = 0; x < len; x++) {
    if (frames[x] != null) {
        if (frames[x].textRange != null) {
            if (frames[x].textRange.characterAttributes != null) {
                if (frames[x].textRange.characterAttributes.textFont != null) {
                    if (frames[x].textRange.characterAttributes.textFont.name != null) {
                        if (frames[x].textRange.characterAttributes.textFont.name.toLowerCase().indexOf("avenir") >= 0 && avenirFonts.indexOf(frames[x].textRange.characterAttributes.textFont.name) < 0) {
                            avenirFonts = avenirFonts + frames[x].textRange.characterAttributes.textFont.name + "\n";
                        }
                    }
                }
            }
        }
    }
}

if (avenirFonts.length > 0) {
    throw "Found Avenir Fonts: " + avenirFonts;
}

  The purpose of this script is to replace the Apple Avenir fonts to a windows available font, and it will work even if I receive an error after a few retries. We have automation built out to create AI templates from source files ever 5 minutes to assist our design team.

[AndrewBancroft00]

"TryFixIllustratorFonts: Exception has been thrown by the target of an invocation. Error 45: Object is invalid.Line: 5-> if (frames[x] != null) {"

I've also seen this error. Is there a place to look up the error codes for 1220 and 45?

[femkeblanco]

The "Illegal Argument" error could be caused by "textFont" when the string is empty. Furthermore, when an object is absent, Illustrator throws an error (no such element) as soon as the object expression is evaluated. So there is no point testing it with "null". Try using "try...catch" instead of conditionals.