1. A computer-implemented method of handling content availability error codes, the computer-implemented method comprising: receiving, at a buffer in a client computer, a content request response, wherein the content request response is received by the buffer in response to a content request, from a content renderer in the client computer, to update displayed content on a user interface on the client computer, wherein the content request response is stored in the buffer, and wherein the buffer is isolated from the content renderer; and transmitting the content request response from the buffer to a content request response handler in the client computer, wherein the content request response handler prevents the content request response from being sent directly from the buffer to the content renderer without the content request response first being analyzed by the content request response handler.