"Uncaught TypeError: modal.modal is not a function at show_modal " - problem on only chrome and in development level.

[xeroticikot]

I'm facing this weird bug during development on Chrome browser, clicking on the instance selector button returns the console error below -

Uncaught TypeError: modal.modal is not a function
    at show_modal (instance_selector_widget.js:82)
    at HTMLIFrameElement.<anonymous> (instance_selector_widget.js:44)
    at HTMLIFrameElement.dispatch (px-jquery-1.7.1.min.js:3)
    at HTMLIFrameElement.i (px-jquery-1.7.1.min.js:3)

and the selector option wouldn't open. Any idea what's going wrong?