In fact, Canon printers use a series of gold-colored contacts on the front of the cartridge, which is the only point of contact with the cartridge. If these contacts are covered with dirt, ink or natural oils from your hands, the message will be displayed. Be that as it may, Canon's customer service team recommended a simple solution to this problem. Hence, here this article will walk you through some basic steps on how to troubleshoot the E04 Canon printer error. So just try the steps below to fix the problem right away, we wish your problem is resolved after following all the steps above.