Note: the non-selectable slider is not an FSB error.
It is a Firefox error that came up with v.59.
Again-Note. No matter which version of FSB is running your site, the slider will not work in FF v.59 because it is a problem in the FF browser.
Below is a temporary patch that will solve this problem. Simply place it in the section of your footer in parameters and save it. Remove cache if you do not see immediate results.