I'm trying to figure out why I get this error from some visitors via my JS error console tracker:

> 
> Uncaught TypeError: Cannot read property 'classList' of null
> 
> 
> 

The code in question is:

```
                if (typeof item == "object") {
                    item.classList.remove('active');
                    update_specific_marker(item.getAttribute('data-what'),"remove_active_icon");
                }

```

Shouldn't this bit work:

```
if (typeof item == "object") {

```

I'm baffled as to how they get it in the first place - as I can't get any errors to come out from that page (no matter how much I play with it, even in Chrome which is where it seems to come from)

Any suggestions on what I could try?