The Epson printer offline error occurs due to network connection problems or mistakenly setting your printer on offline mode. To fix this error, firstly, you need to rectify the network connection, and if the problem exists, then following some advanced troubleshooting steps. Visit the Control Panel section on your computer and click devices, and printers now select your Epson printer from the list. After that, click open print queues and hit the printer tab, further uncheck the option Use Printer Offline and click Set as default printer. Additionally, you must always update your Epson printer driver to the latest software, and if still, the problem persists, then you can uninstall and reinstall the driver from Epson's website.