To resolve the Epson WF-3640 Offline issue, unplug your router's power cord from the power outlet. Then, after a brief delay, plug it back in. Additionally, try printing (The connection for the other devices on your network might need to be re-established). The last step is to print if you're done. Initializing your router addressed the issue. Try restarting your computer, then try printing again if you're still having trouble. You can contact Epson support if these instructions do not help you address your issue.