Script not working after update - Acrobat Reader DC

Acrobat Reader DC v2017.012.20095

Windows 10 v10.0.15063

I have a script "PrintFilename.js" in the following folder:

C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\Javascripts

The script adds a menu item and looks like this:

app.addMenuItem({cName:"Show Filename", cParent:"File", nPos:20, cExec:"AddFilename();"});

function AddFilename()

{

var re = /.*\/|\.pdf$/ig;

var MyFileName = this.path.replace(re,"");

for (var p = 0; p < this.numPages; p++)

{

var fd = this.addField("MyFilenameField", "text", p, [18,825, 500,840]);

fd.textSize=10;

fd.textColor = color.blue;

fd.value = MyFileName;

}

}

Last time I used it was on July 1st but now that I want to use the menu item I realise that it is no longer there. So something has happened after an update between July 1st and now. Either the script does not fire, or the code has stopped working.

Any ideas?