403 error when embedding YouTube video
Here's the code I use for embedding, which is very similar to yours, except that you're missing the ?rel=0&controls=1&showinfo=0" after the YouTube Short Code (everything after the /embed/).
I use the info 4 field in an image to hold the YouTube Short Code but you can use a separate text field as well
<iframe width="500" height="300" style="border:medium double #333333" src="https://www.youtube.com/embed/<?php foreach ($salon_e_blastsRecord['images'] as $index => $upload): ?><?php echo $upload['info4'] ?><?php endforeach ?>?rel=0&controls=1&showinfo=0" frameborder="0" allowfullscreen></iframe>
The only other differences that I see is the added switches like accelerometer encrypted, etc. I'd try adding the ?rel=0&controls=1&showinfo=0" and possibly eliminating all but the switches that I use and see what happens. Then add them back one at a time.
Hope that helps
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