Note :
Do not use bullet Characters in your comments.
i.e
/*
• some item comment
*/
I had some in one of my extensions hypeDocument.TypeTextExtension. Which I was using in a project. ( now updated )
I also wanted to have a border around the scene so used my Export Script.
In this case the Borders would not show up in the export, no errors evident.
After some extensive head scratching, I found it to be the Bullets symbols/Characters in the comments of the head Extension.
Not sure why this would happen but clearly either the hype runtime or the Browser engines Safari/Chrome are running into an issue when parsing them.
So if like me you have used them in comments, probably a good idea to remove them.