I am trying to bulk optimize all the images on my website

Hi,

I am trying to bulk optimize all the images on my website with WP Smush it, but it keeps freezing after a few images are optimized and doesn't optimize any further images. As seen here: http://i.imgur.com/lewv7Ga.png

I have enabled support access on the dashboard.

What can I do in future to ensure this doesn't happen? I have quite a few more website I'd like to utilize smush it on.

Thanks for any help in advance,
Luke