So the error I was receiving was “invalid token o”.
Until I figured out the problem – the error was coming up on a callback from a jQuery AJAX POST. My normal mechanism on these is to parse the returned data string into a JSON object, then do my work against that object.
However, this particular AJAX POST was already returning it as an object. So when I did my “JSON.parse(data)”, it converted ‘data’ into “[object Object]“. And guess what? That is not valid JSON! So guess what, that ‘o’ is an invalid token!
Yeah, an hour of futzing around only to realize that I didn’t need to parse that object.