The 504 Gateway Timeout error is an HTTP status code that indicates that one server did not receive a timely response from another server that it was accessing while attempting to load the web page or execute another request from the browser.
Try the web page again by clicking the Refresh/Reload button, pressing F5, or retrying the URL in the address bar.
Even though the 504 Gateway Timeout error indicates an error beyond your control, it is possible that the error is only temporary.
Reboot all of your network devices. Temporary issues with your modem, router, switches, or other network hardware could be causing the 504 Gateway Timeout issue you are seeing. Rebooting these devices may help.