This sounds like interpreter.js is removed at some point, possibly after the relevant component is unmounted. The GuidedTrack program, when it loads, starts listening for certain events to figure out when it's time to sync the data with the server. It might be that one of those is trying to run after interpreter.js is already not on the page.
Could you describes the exact steps you take before running into this problem? Are there any adverse effects other than seeing the error you describe in the console?