Yes, it seems to me too but in the page source I just find the same error in the library code, it's weird because the function is actually defined and on a local server (without using LS) it works. So I don't know how to fix.
But no worries, I switched to another library now! Unfortunately it's not open source and easy to use like webgazer but I'll see what I can do.

I see pjax : the pjax system is old, what is your limesurvey version ?

I'm editing on the online editor, so it should be the latest (I think)

I'm editing on the online editor, so it should be the latest (I think)

Limesurvey is an online application, so this can be ANY version. I see versions of Limesurvey in the forum that are 7 or more years old.

So you need to provide the exact version. You can usually find it at the bottom right corner of any Limesurvey Admin page.

So many things I didn't know! Thank you, I just checked and it's version 3.27.16

My opinion : your surveytheme include some old javascript that broke other javascript

Yes, do you get any other errors in the browser console (F12)?

This is everything I'm getting on the console, the only errors are those two