After I updated to 1.5 my mobile menu stopped working as well as my lightbox script. I didn't change these things as far as I know.

Here's a test page that has a few lightbox images and the mobile menu for small screens.
http://villageworkroom.coffeecup.com/products.html

Any ideas?

Hey, Joe!

Version 1.5 no longer includes jQuery with the software. If your Lightbox uses jQuery, make sure to include those libraries in your project and add the corresponding markup for them under the Settings pane.

https://developers.google.com/speed/libraries/

Great, thanks, that was an easy fix. Do you now not recommend using jQuery?

Not at all! RSD itself just does not use it, so we saw no need to load down the software with things that are not required.