IE10 console does not return line number on javascript error?

Question

I am getting this error in the console ( which I do not get in Safari or Firefox )

"Unable to get property 'split' of undefined or null reference" 

But there is no line number. ( Previously, when I received different errors in Firefox and Safari a line number is reported )

Does IE not know where the code it is running is, or does it just not want to tell me.

Answer 1

Get IE to fire a breakpoint in its debugger when the exception happens: F12 / Script / Tools dropdown / Break on unhandled exceptions, then Start Debugging.