TypeError: Converting circular structure to JSON in custom library

I'm working on a small project and I wanted to export an array of JSON objects into a text file. I came across this handy console.save() function for Chrome Dev Tools, and decided to use it. My library, leapcapjs has an exposed function that is the following:

LeapCap.getSavedFrames = function(){
    return SAVED_FRAMES;
} 

where SAVED_FRAMES is a global variable. In order to export this array to a string, I typed the following into my dev console:

console.save(LeapCap.getSavedFrames());

As a result, I get the following error:

TypeError: Converting circular structure to JSON 

Anyone know what the problem could be? Thanks!

EDIT: SAVED_FRAMES is populated with frameData objects:

SAVED_FRAMES.push(frameData);

A frameData object is made like this:

LEAP_CONTROLLER.on('frame', function (frame) {
        if (!PAUSE_LEAP) {
            var frameData = {
                'interaction_box': frame.interactionBox,
                'hands': frame.hands
            };
            drawWith(frameData);
        }
    });

Could some of the LeapJS API objects be causing the problem? If so, how can I stop this?