Uncaught TypeError: Cannot read property 'undefined' of undefined

[lcnvdl]

I just added:

<script src="js/watch.js"></script>

Using the last version of Google Chrome.

And i get an infinite error:
Uncaught TypeError: Cannot read property 'undefined' of undefined

in line:
var difference = getObjDiff(subj.obj[subj.prop], subj.actual);

[cemrich]

I just had a similar issue with

Uncaught TypeError: Cannot read property '<propertyName>' of undefined 

inside getObjDiff (after deleting an attribute). Updating to the latest version fixed this error for me.