text: what does "a248.e.akamai.net has sent error code _____" mean? i use firefox and the browser said "a248.e.akamai.net has sent error code _____"...what does it mean? well, its complicated. in simplest terms, a web ad or banner ad was supposed to show up on a webpage that you were on.  the ad did not show, however, and an error code was supplied. the code will be seen by the company who made the ad....so that they can see what failed.