Error: Trouble evaluating response: Unexpected token

I have an error getting for only one user mentioned below. Could some one think of what could be the problem. Rest of the users seems fine.

JavaScript Error:
Error: Trouble evaluating response: Unexpected token <

That is typical of a JavaScript containing the wrong character, like for instance a missing or misplaced quote.

Ask the user to send you the full content of the upper field in the JavaScript error black box. These three lines are only the beginning of a much longer text he can select with Ctrl-A or Cmd-A before copying.

The source of the error is much below, probably enclosed in a tag.

PS : It appears the error box is black in Mac, but can be another color in Windows.

The customer has send me the screen shot and the error box contains nothing except the one i mentioned above. and from the error log in the server side also contain only those wordings. I am a bit confused as i am not getting this error.

A screen shot won’t show you all that is in the upper field of the box. It scrolls. Try to explain to your customer you want the entire content of that box, not just a screen shot.

As it stands, the message you got only tells the issue is somewhere on the page.

Do you know which page it is ? Do you use any JavaScript in there ?

I dont use any Javascript. Normally when the user sends the error back to server, it contain all the error messages. and this contains only the error that i mentioned.

I will ask the user in which page the error is showing.

Find out which browser and OS they’re using. If you can replicate it, it will be easier to track down.