Revolution Slider Stuck on Slide 1

I am helping someone manage their WordPress site, which has HighEnd installed utilizing RevolutionSlider. Recently, the slider stopped working correctly. There are four slides, but the slider is stuck on #1, the navigation arrows do not appear, and the text box of a second layer seems to have formatting that has gone wrong. It seems like a global settings issue, rather than an issue with the slider. The url is institutefordevelopmentimpact.com

Please advise. Thanks.