Your comments

I have not done a lot of testing but seems fixed. I am no longer hitting the Entry Process of my shared hosting which was happening quite often before (the limit is 20 so I only had to open/close the window 20 times). Thanks again for fixing it and for the amazing app. Keep up the good work. 

Thanks for the quick fix. I already updated the app but I have not tried it yet. I will give it a try later today or tomorrow.

Any luck reproducing the problem? As someone suggested the best way might be to just add an alert() window in JS. You’ll notice it will start popping up more than once after using the preview window for a while. Thanks for the lovely app!

I also have seen what Doug reported when I added an alert to a javascript hence why I suspected the window was not getting closed from previous sessions. Sometimes I would have to close the alert several multiple times. This a bit more serious when using a shared hosting where the Entry Process limit is set to 30 or 20 making you hit the limit quite easily and getting 508s from the backend. This needs a quick fix.