Chrome Extension sendMessage error from content script to background html -
    i updated chrome extension json version 2, , trying extension work again. problem sendrequest depreciated along way.  copy code https://developer.chrome.com/extensions/messaging.html   script , modify own variable names, , doesn't work.   so go , put in original code , still doesn't work.  have read multiple questions similar [and won't closed duplicate, because none of them same situation].   manifest.json:   {    "background": {         "page": "background.html"         },     ... ... ...    "content_scripts": [ {       "css": [ "style.css" ],       "js": [ "jq.js", "script.js" ],       "matches": [ "http://*.craigslist.org/*/*.htm*" ]    } ],    ... ... ...    "permissions": [ "tabs", "http://*.craigslist.org/*/*.htm*" ],    "manifest_version": 2,    "update_url": "http://clients2.google.com/service/updat...